Independent Orbiter Assessment (IOA): Analysis of the electrical power distribution and control/remote manipulator system subsystem

NASA Technical Reports Server (NTRS)

Robinson, W. W.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the Electrical Power Distribution and Control (EPD and C)/Remote Manipulator System (RMS) hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained in the NASA FMEA/CIL documentation. This report documents the results of the independent analysis of the EPD and C/RMS (both port and starboard) hardware. The EPD and C/RMS subsystem hardware provides the electrical power and power control circuitry required to safely deploy, operate, control, and stow or guillotine and jettison two (one port and one starboard) RMSs. The EPD and C/RMS subsystem is subdivided into the four following functional divisions: Remote Manipulator Arm; Manipulator Deploy Control; Manipulator Latch Control; Manipulator Arm Shoulder Jettison; and Retention Arm Jettison. The IOA analysis process utilized available EPD and C/RMS hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based on the severity of the effect for each failure mode.

Independent Orbiter Assessment (IOA): Analysis of the manned maneuvering unit

NASA Technical Reports Server (NTRS)

Bailey, P. S.

1986-01-01

Results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve indepedence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Manned Maneuvering Unit (MMU) hardware. The MMU is a propulsive backpack, operated through separate hand controllers that input the pilot's translational and rotational maneuvering commands to the control electronics and then to the thrusters. The IOA analysis process utilized available MMU hardware drawings and schematics for defining hardware subsystems, assemblies, components, and hardware items. Final levels of detail were evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the worst case severity of the effect for each identified failure mode. The IOA analysis of the MMU found that the majority of the PCIs identified are resultant from the loss of either the propulsion or control functions, or are resultant from inability to perform an immediate or future mission. The five most severe criticalities identified are all resultant from failures imposed on the MMU hand controllers which have no redundancy within the MMU.

Remote maintenance monitoring system

NASA Technical Reports Server (NTRS)

Simpkins, Lorenz G. (Inventor); Owens, Richard C. (Inventor); Rochette, Donn A. (Inventor)

1992-01-01

A remote maintenance monitoring system retrofits to a given hardware device with a sensor implant which gathers and captures failure data from the hardware device, without interfering with its operation. Failure data is continuously obtained from predetermined critical points within the hardware device, and is analyzed with a diagnostic expert system, which isolates failure origin to a particular component within the hardware device. For example, monitoring of a computer-based device may include monitoring of parity error data therefrom, as well as monitoring power supply fluctuations therein, so that parity error and power supply anomaly data may be used to trace the failure origin to a particular plane or power supply within the computer-based device. A plurality of sensor implants may be rerofit to corresponding plural devices comprising a distributed large-scale system. Transparent interface of the sensors to the devices precludes operative interference with the distributed network. Retrofit capability of the sensors permits monitoring of even older devices having no built-in testing technology. Continuous real time monitoring of a distributed network of such devices, coupled with diagnostic expert system analysis thereof, permits capture and analysis of even intermittent failures, thereby facilitating maintenance of the monitored large-scale system.

Independent Orbiter Assessment (IOA): Assessment of the auxiliary power unit

NASA Technical Reports Server (NTRS)

Barnes, J. E.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Auxiliary Power Unit (APU) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter APU hardware. The IOA product for the APU analysis, covering both APU hardware and APU electrical components, consisted of 344 failure mode worksheets that resulted in 178 potential critical items being identified. A comparison was made of the IOA product to the NASA APU hardware FMEA/CIL baseline which consisted of 184 FMEAs and 57 CIL items. The comparison identified 72 discrepancies.

Automatisms in EMIR instrument to improve operation, safety and maintenance

NASA Astrophysics Data System (ADS)

Fernández Izquierdo, Patricia; Núñez Cagigal, Miguel; Barreto Rodríguez, Roberto; Martínez Rey, Noelia; Santana Tschudi, Samuel; Barreto Cabrera, Maria; Patrón Recio, Jesús; Garzón López, Francisco

2014-08-01

EMIR is the NIR imager and multiobject spectrograph being built as a common user instrument for the 10-m class GTC. Big cryogenic instruments demand a reliable design and a specific hardware and software to increase its safety and productivity. EMIR vacuum, cooling and heating systems are monitored and partially controlled by a Programmable Logic Controller (PLC) in industrial format with a touch screen. The PLC aids the instrument operator in the maintenance tasks recovering autonomously vacuum if required or proposing preventive maintenance actions. The PLC and its associated hardware improve EMIR safety having immediate reactions against eventual failure modes in the instrument or in external supplies, including hardware failures during the heating procedure or failure in the PLC itself. EMIR PLC provides detailed information periodically about status and alarms of vacuum and cooling components or external supplies.

VIDANA: Data Management System for Nano Satellites

NASA Astrophysics Data System (ADS)

Montenegro, Sergio; Walter, Thomas; Dilger, Erik

2013-08-01

A Vidana data management system is a network of software and hardware components. This implies a software network, a hardware network and a smooth connection between both of them. Our strategy is based on our innovative middleware. A reliable interconnection network (SW & HW) which can interconnect many unreliable redundant components such as sensors, actuators, communication devices, computers, and storage elements,... and software components! Component failures are detected, the affected device is disabled and its function is taken over by a redundant component. Our middleware doesn't connect only software, but also devices and software together. Software and hardware communicate with each other without having to distinguish which functions are in software and which are implemented in hardware. Components may be turned on and off at any time, and the whole system will autonomously adapt to its new configuration in order to continue fulfilling its task. In VIDANA we aim dynamic adaptability (run tine), static adaptability (tailoring), and unified HW/SW communication protocols. For many of these aspects we use "learn from the nature" where we can find astonishing reference implementations.

Independent Orbiter Assessment (IOA): Analysis of the elevon subsystem

NASA Technical Reports Server (NTRS)

Wilson, R. E.; Riccio, J. R.

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results for the Orbiter Elevon system hardware. The elevon actuators are located at the trailing edge of the wing surface. The proper function of the elevons is essential during the dynamic flight phases of ascent and entry. In the ascent phase of flight, the elevons are used for relieving high wing loads. For entry, the elevons are used to pitch and roll the vehicle. Specifically, the elevon system hardware comprises the following components: flow cutoff valve; switching valve; electro-hydraulic (EH) servoactuator; secondary delta pressure transducer; bypass valve; power valve; power valve check valve; primary actuator; primary delta pressure transducer; and primary actuator position transducer. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Of the 25 failure modes analyzed, 18 were determined to be PCIs.

Independent Orbiter Assessment (IOA): Analysis of the nose wheel steering subsystem

NASA Technical Reports Server (NTRS)

Mediavilla, Anthony Scott

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbiter Nose Wheel Steering (NWS) hardware are documented. The NWS hardware provides primary directional control for the Orbiter vehicle during landing rollout. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. The original NWS design was envisioned as a backup system to differential braking for directional control of the Orbiter during landing rollout. No real effort was made to design the NWS system as fail operational. The brakes have much redundancy built into their design but the poor brake/tire performance has forced the NSTS to upgrade NWS to the primary mode of directional control during rollout. As a result, a large percentage of the NWS system components have become Potential Critical Items (PCI).

Semiannual Technical Summary, 1 April-30 September 1993

DTIC Science & Technology

1993-12-01

Hardware failure 11 Jul 2200 - Hardware failure 12 Jul - 0531 Hardware failure 12 Jul 0744 - 1307 Hardware service 1OAug 0821 - 1514 Line failure 29 Aug...1000 - Line failure 30 Aug - 1211 Line failure 08 Sep 1518 - Line failure 09 Sep - 0428 Line failure 10 Sep 0821 - 1030 Hardware failure 18 Sep 0817...reair. Between 8 September 1306 hrs and 9 September 0428 hre all communications systems wene affected (13.5 hrs). Reduced 01B performance started 10

Long life assurance study for manned spacecraft long life hardware. Volume 3: Long life assurance studies of components

NASA Technical Reports Server (NTRS)

1972-01-01

The guidelines for selecting hardware to be used in manned spacecraft to obtain a five year operational lifetime without maintenance were developed. An analysis was conducted on the design, application, failure mechanisms, manufacturing processes and controls, screen and burn-in techniques, and quality control of hardware items. The equipment considered for evaluation include: (1) electric motors and bearings; (2) accelerometers; (3) gyroscopes and bearings; (4) compressors and pumps, (5) magnetic tape recorders; (6) plumbing components and tubing; (7) check valves; (8) pressure regulators and solenoid valves; (9) thermal control valves; (10) pressure vessels and positive expulsion devices; (11) nickel cadmium batteries; and (12) transducers.

Independent Orbiter Assessment (IOA): Weibull analysis report

NASA Technical Reports Server (NTRS)

Raffaelli, Gary G.

1987-01-01

The Auxiliary Power Unit (APU) and Hydraulic Power Unit (HPU) Space Shuttle Subsystems were reviewed as candidates for demonstrating the Weibull analysis methodology. Three hardware components were identified as analysis candidates: the turbine wheel, the gearbox, and the gas generator. Detailed review of subsystem level wearout and failure history revealed the lack of actual component failure data. In addition, component wearout data were not readily available or would require a separate data accumulation effort by the vendor. Without adequate component history data being available, the Weibull analysis methodology application to the APU and HPU subsystem group was terminated.

Independent Orbiter Assessment (IOA): Analysis of the landing/deceleration subsystem

NASA Technical Reports Server (NTRS)

Compton, J. M.; Beaird, H. G.; Weissinger, W. D.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Landing/Deceleration Subsystem hardware. The Landing/Deceleration Subsystem is utilized to allow the Orbiter to perform a safe landing, allowing for landing-gear deploy activities, steering and braking control throughout the landing rollout to wheel-stop, and to allow for ground-handling capability during the ground-processing phase of the flight cycle. Specifically, the Landing/Deceleration hardware consists of the following components: Nose Landing Gear (NLG); Main Landing Gear (MLG); Brake and Antiskid (B and AS) Electrical Power Distribution and Controls (EPD and C); Nose Wheel Steering (NWS); and Hydraulics Actuators. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Due to the lack of redundancy in the Landing/Deceleration Subsystems there is a high number of critical items.

A Summary of Taxonomies of Digital System Failure Modes Provided by the DigRel Task Group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chu T. L.; Yue M.; Postma, W.

2012-06-25

Recently, the CSNI directed WGRisk to set up a task group called DIGREL to initiate a new task on developing a taxonomy of failure modes of digital components for the purposes of PSA. It is an important step towards standardized digital I&C reliability assessment techniques for PSA. The objective of this paper is to provide a comparison of the failure mode taxonomies provided by the participants. The failure modes are classified in terms of their levels of detail. Software and hardware failure modes are discussed separately.

Failure analysis on optical fiber on swarm flight payload

NASA Astrophysics Data System (ADS)

Bourcier, Frédéric; Fratter, Isabelle; Teyssandier, Florent; Barenes, Magali; Dhenin, Jérémie; Peyriguer, Marie; Petre-Bordenave, Romain

2017-11-01

Failure analysis on optical components is usually carried-out, on standard testing devices such as optical/electronic microscopes and spectrometers, on isolated but representative samples. Such analyses are not contactless and not totally non-invasive, so they cannot be used easily on flight models. Furthermore, for late payload or satellite integration/validation phases with tight schedule issues, it could be necessary to carry out a failure analysis directly on the flight hardware, in cleanroom.

Relating design and environmental variables to reliability

NASA Astrophysics Data System (ADS)

Kolarik, William J.; Landers, Thomas L.

The combination of space application and nuclear power source demands high reliability hardware. The possibilities of failure, either an inability to provide power or a catastrophic accident, must be minimized. Nuclear power experiences on the ground have led to highly sophisticated probabilistic risk assessment procedures, most of which require quantitative information to adequately assess such risks. In the area of hardware risk analysis, reliability information plays a key role. One of the lessons learned from the Three Mile Island experience is that thorough analyses of critical components are essential. Nuclear grade equipment shows some reliability advantages over commercial. However, no statistically significant difference has been found. A recent study pertaining to spacecraft electronics reliability, examined some 2500 malfunctions on more than 300 aircraft. The study classified the equipment failures into seven general categories. Design deficiencies and lack of environmental protection accounted for about half of all failures. Within each class, limited reliability modeling was performed using a Weibull failure model.

Independent Orbiter Assessment (IOA): Analysis of the electrical power generation/power reactant storage and distribution subsystem

NASA Technical Reports Server (NTRS)

Gotch, S. M.

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NAA FMEA/CIL documentation. The independent analysis results corresponding to the Orbiter Electrical Power Generation (EPG)/Power Reactants Storage and Distribution (PRSD) System Hardware is documented. The EPG/PRSD hardware is required for performing critical functions of cryogenic hydrogen and oxygen storage and distribution to the Fuel Cell Powerplants (FCP) and Atmospheric Revitalization Pressure Control Subsystem (ARPCS). Specifically, the EPG/PRSD hardware consists of the following: Hydryogen (H2) tanks; Oxygen (O2) tanks; H2 Relief Valve/Filter Packages (HRVFP); O2 Relief Valve/Filter Packages (ORVFP); H2 Valve Modules (HVM); O2 Valve Modules (OVM); and O2 and H2 lines, components, and fittings.

Correlation study between vibrational environmental and failure rates of civil helicopter components

NASA Technical Reports Server (NTRS)

Alaniz, O.

1979-01-01

An investigation of two selected helicopter types, namely, the Models 206A/B and 212, is reported. An analysis of the available vibration and reliability data for these two helicopter types resulted in the selection of ten components located in five different areas of the helicopter and consisting primarily of instruments, electrical components, and other noncritical flight hardware. The potential for advanced technology in suppressing vibration in helicopters was assessed. The are still several unknowns concerning both the vibration environment and the reliability of helicopter noncritical flight components. Vibration data for the selected components were either insufficient or inappropriate. The maintenance data examined for the selected components were inappropriate due to variations in failure mode identification, inconsistent reporting, or inaccurate informaton.

Software Health Management: A Short Review of Challenges and Existing Techniques

NASA Technical Reports Server (NTRS)

Pipatsrisawat, Knot; Darwiche, Adnan; Mengshoel, Ole J.; Schumann, Johann

2009-01-01

Modern spacecraft (as well as most other complex mechanisms like aircraft, automobiles, and chemical plants) rely more and more on software, to a point where software failures have caused severe accidents and loss of missions. Software failures during a manned mission can cause loss of life, so there are severe requirements to make the software as safe and reliable as possible. Typically, verification and validation (V&V) has the task of making sure that all software errors are found before the software is deployed and that it always conforms to the requirements. Experience, however, shows that this gold standard of error-free software cannot be reached in practice. Even if the software alone is free of glitches, its interoperation with the hardware (e.g., with sensors or actuators) can cause problems. Unexpected operational conditions or changes in the environment may ultimately cause a software system to fail. Is there a way to surmount this problem? In most modern aircraft and many automobiles, hardware such as central electrical, mechanical, and hydraulic components are monitored by IVHM (Integrated Vehicle Health Management) systems. These systems can recognize, isolate, and identify faults and failures, both those that already occurred as well as imminent ones. With the help of diagnostics and prognostics, appropriate mitigation strategies can be selected (replacement or repair, switch to redundant systems, etc.). In this short paper, we discuss some challenges and promising techniques for software health management (SWHM). In particular, we identify unique challenges for preventing software failure in systems which involve both software and hardware components. We then present our classifications of techniques related to SWHM. These classifications are performed based on dimensions of interest to both developers and users of the techniques, and hopefully provide a map for dealing with software faults and failures.

Potential Damage to Flight Hardware from MIL-STD-462 CS02 Setup

NASA Technical Reports Server (NTRS)

Harris, Patrick K.; Block, Nathan F.

2003-01-01

The MIL-STD-462 CS02 conducted susceptibility test setup includes an audio transformer, with the secondary used as an inductor, and a large capacitor. Together, these two components form an L-type low-pass filter to minimize the injected test signal input into the power source. Some flight hardware power input configurations are not compatible with this setup and break into oscillation when powered up. This, in turn, can damage flight hardware. Such an oscillation resulted in the catastrophic failure of an item tested in the Goddard Space Flight Center (GSFC) Large electromagnetic compatibility (EMC) Test Facility.

Potential Damage to Flight Hardware from MIL-STD-462 CS02 Setup

NASA Technical Reports Server (NTRS)

Harris, Patrick K.; Block, Nathan F.

2002-01-01

The MIL-STD-462 CS02 conducted susceptibility test setup, performed during electromagnetic compatibility (EMC) testing, consists of an audio transformer with the secondary used as an inductor and a large capacitor. Together, these two components form an L-type low-pass filter to minimize the injected test signal input into the power source. Some flight hardware power input configurations are not compatible with this setup and break into oscillation when powered up. This can damage flight hardware and caused a catastrophic failure to an item tested in the Goddard Space Flight Center (GSFC) Large EMC Test Facility.

A Study to Compare the Failure Rates of Current Space Shuttle Ground Support Equipment with the New Pathfinder Equipment and Investigate the Effect that the Proposed GSE Infrastructure Upgrade Might Have to Reduce GSE Infrastructure Failures

NASA Technical Reports Server (NTRS)

Kennedy, Barbara J.

2004-01-01

The purposes of this study are to compare the current Space Shuttle Ground Support Equipment (GSE) infrastructure with the proposed GSE infrastructure upgrade modification. The methodology will include analyzing the first prototype installation equipment at Launch PAD B called the "Pathfinder". This study will begin by comparing the failure rate of the current components associated with the "Hardware interface module (HIM)" at the Kennedy Space Center to the failure rate of the neW Pathfinder components. Quantitative data will be gathered specifically on HIM components and the PAD B Hypergolic Fuel facility and Hypergolic Oxidizer facility areas which has the upgraded pathfinder equipment installed. The proposed upgrades include utilizing industrial controlled modules, software, and a fiber optic network. The results of this study provide evidence that there is a significant difference in the failure rates of the two studied infrastructure equipment components. There is also evidence that the support staff for each infrastructure system is not equal. A recommendation to continue with future upgrades is based on a significant reduction of failures in the new' installed ground system components.

Data Applicability of Heritage and New Hardware For Launch Vehicle Reliability Models

NASA Technical Reports Server (NTRS)

Al Hassan, Mohammad; Novack, Steven

2015-01-01

Bayesian reliability requires the development of a prior distribution to represent degree of belief about the value of a parameter (such as a component's failure rate) before system specific data become available from testing or operations. Generic failure data are often provided in reliability databases as point estimates (mean or median). A component's failure rate is considered a random variable where all possible values are represented by a probability distribution. The applicability of the generic data source is a significant source of uncertainty that affects the spread of the distribution. This presentation discusses heuristic guidelines for quantifying uncertainty due to generic data applicability when developing prior distributions mainly from reliability predictions.

Biomechanical comparison of component position and hardware failure in the reverse shoulder prosthesis.

PubMed

Gutiérrez, Sergio; Greiwe, R Michael; Frankle, Mark A; Siegal, Steven; Lee, William E

2007-01-01

There has been renewed interest in reverse shoulder arthroplasty for the treatment of glenohumeral arthritis with concomitant rotator cuff deficiency. Failure of the prosthesis at the glenoid attachment site remains a concern. The purpose of this study was to examine glenoid component stability with regard to the angle of implantation. This investigation entailed a biomechanical analysis to evaluate forces and micromotion in glenoid components attached to 12 polyurethane blocks at -15 degrees, 0 degrees, and +15 degrees of superior and inferior tilt. The 15 degrees inferior tilt had the most uniform compressive forces and the least amount of tensile forces and micromotion when compared with the 0 degrees and 15 degrees superiorly tilted baseplate. Our results suggest that implantation with an inferior tilt will reduce the incidence of mechanical failure of the glenoid component in a reverse shoulder prosthesis.

Experiences with Extra-Vehicular Activities in Response to Critical ISS Contingencies

NASA Technical Reports Server (NTRS)

Van Cise, E. A.; Kelly, B. J.; Radigan, J. P.; Cranmer, C. W.

2016-01-01

The maturation of the International Space Station (ISS) design from the proposed Space Station Freedom to today's current implementation resulted in external hardware redundancy vulnerabilities in the final design. Failure to compensate for or respond to these vulnerabilities could put the ISS in a posture to where it could no longer function as a habitable space station. In the first years of ISS assembly, these responses were to largely be addressed by the continued resupply and Extra-Vehicular Activity (EVA) capabilities of the Space Shuttle. Even prior to the decision to retire the Space Shuttle, it was realized that ISS needed to have its own capability to be able to rapidly repair or replace external hardware without needing to wait for the next cargo resupply mission. As documented in a previous publicatoin5, in 2006 development was started to baseline Extra- Vehicular Activity (EVA, or spacewalk) procedures to replace hardware components whose failure would expose some of the ISS vulnerabilities should a second failure occur. This development work laid the groundwork for the onboard crews and the ground operations and engineering teams to be ready to replace any of this failed hardware. In 2010, this development work was put to the test when one of these pieces of hardware failed. This paper will provide a brief summary of the planning and processes established in the original Contingency EVA development phase. It will then review how those plans and processes were implemented in 2010, highlighting what went well as well as where there were deficiencies between theory and reality. This paper will show that the original approach and analyses, though sound, were not as thorough as they should have been in the realm of planning for next worse failures, for documenting Programmatic approval of key assumptions, and not pursuing sufficient engineering analysis prior to the failure of the hardware. The paper will further highlight the changes made to the Contingency EVA preparation team structure, approach, goals, and the resources allocated to its work after the 2010 events. Finally, the authors will overview the implementation of these updates in addressing failures onboard the ISS in 2012, 2013, and 2014. The successful use of the updated approaches, and the application of the approaches to other spacewalks, will demonstrate the effectiveness of this additional work and make a case for putting significant time and resources into pre-failure planning and analysis for critical hardware items on human-tended spacecraft.

Experiences with Extra-Vehicular Activities in Response to Critical ISS Contingencies

NASA Technical Reports Server (NTRS)

Van Cise, E. A.; Kelly, B. J.; Radigan, J. P.; Cranmer, C. W.

2016-01-01

The maturation of the International Space Station (ISS) design from the proposed Space Station Freedom to today's current implementation resulted in external hardware redundancy vulnerabilities in the final design. Failure to compensate for or respond to these vulnerabilities could put the ISS in a posture where it could no longer function as a habitable space station. In the first years of ISS assembly, these responses were to largely be addressed by the continued resupply and Extra-Vehicular Activity (EVA) capabilities of the Space Shuttle. Even prior to the decision to retire the Space Shuttle, it was realized that ISS needed to have its own capability to be able to rapidly repair or replace external hardware without needing to wait for the next cargo resupply mission. As documented in a previous publication, in 2006 development was started to baseline Extra-Vehicular Activity (EVA, or spacewalk) procedures to replace hardware components whose failure would expose some of the ISS vulnerabilities should a second failure occur. This development work laid the groundwork for the onboard crews and the ground operations and engineering teams to be ready to replace any of this failed hardware. In 2010, this development work was put to the test when one of these pieces of hardware failed. This paper will provide a brief summary of the planning and processes established in the original Contingency EVA development phase. It will then review how those plans and processes were implemented in 2010, highlighting what went well as well as where there were deficiencies between theory and reality. This paper will show that the original approach and analyses, though sound, were not as thorough as they should have been in the realm of planning for next worse failures, for documenting Programmatic approval of key assumptions, and not pursuing sufficient engineering analysis prior to the failure of the hardware. The paper will further highlight the changes made to the Contingency EVA preparation team structure, approach, goals, and the resources allocated to its work after the 2010 events. Finally, the authors will overview the implementation of these updates in addressing failures onboard the ISS in 2012, 2013, and 2014. The successful use of the updated approaches, and the application of the approaches to other spacewalks, will demonstrate the effectiveness of this additional work and make a case for putting significant time and resources into pre-failure planning and analysis for critical hardware items on human-tended spacecraft.

Independent Orbiter Assessment (IOA): Assessment of the mechanical actuation subsystem, volume 1

NASA Technical Reports Server (NTRS)

Bradway, M. W.; Slaughter, W. T.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine draft failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline that was available. A resolution of each discrepancy from the comparison was provided through additional analysis as required. These discrepancies were flagged as issues, and recommendations were made based on the FMEA data available at the time. This report documents the results of that comparison for the Orbiter Mechanical Actuation System (MAS) hardware. Specifically, the MAS hardware consists of the following components: Air Data Probe (ADP); Elevon Seal Panel (ESP); External Tank Umbilical (ETU); Ku-Band Deploy (KBD); Payload Bay Doors (PBD); Payload Bay Radiators (PBR); Personnel Hatches (PH); Vent Door Mechanism (VDM); and Startracker Door Mechanism (SDM). Criticality was assigned based upon the severity of the effect for each failure mode.

Digital Fly-By-Wire Flight Control Validation Experience

NASA Technical Reports Server (NTRS)

Szalai, K. J.; Jarvis, C. R.; Krier, G. E.; Megna, V. A.; Brock, L. D.; Odonnell, R. N.

1978-01-01

The experience gained in digital fly-by-wire technology through a flight test program being conducted by the NASA Dryden Flight Research Center in an F-8C aircraft is described. The system requirements are outlined, along with the requirements for flight qualification. The system is described, including the hardware components, the aircraft installation, and the system operation. The flight qualification experience is emphasized. The qualification process included the theoretical validation of the basic design, laboratory testing of the hardware and software elements, systems level testing, and flight testing. The most productive testing was performed on an iron bird aircraft, which used the actual electronic and hydraulic hardware and a simulation of the F-8 characteristics to provide the flight environment. The iron bird was used for sensor and system redundancy management testing, failure modes and effects testing, and stress testing in many cases with the pilot in the loop. The flight test program confirmed the quality of the validation process by achieving 50 flights without a known undetected failure and with no false alarms.

Mass and Reliability System (MaRS)

NASA Technical Reports Server (NTRS)

Barnes, Sarah

2016-01-01

The Safety and Mission Assurance (S&MA) Directorate is responsible for mitigating risk, providing system safety, and lowering risk for space programs from ground to space. The S&MA is divided into 4 divisions: The Space Exploration Division (NC), the International Space Station Division (NE), the Safety & Test Operations Division (NS), and the Quality and Flight Equipment Division (NT). The interns, myself and Arun Aruljothi, will be working with the Risk & Reliability Analysis Branch under the NC Division's. The mission of this division is to identify, characterize, diminish, and communicate risk by implementing an efficient and effective assurance model. The team utilizes Reliability and Maintainability (R&M) and Probabilistic Risk Assessment (PRA) to ensure decisions concerning risks are informed, vehicles are safe and reliable, and program/project requirements are realistic and realized. This project pertains to the Orion mission, so it is geared toward a long duration Human Space Flight Program(s). For space missions, payload is a critical concept; balancing what hardware can be replaced by components verse by Orbital Replacement Units (ORU) or subassemblies is key. For this effort a database was created that combines mass and reliability data, called Mass and Reliability System or MaRS. The U.S. International Space Station (ISS) components are used as reference parts in the MaRS database. Using ISS components as a platform is beneficial because of the historical context and the environment similarities to a space flight mission. MaRS uses a combination of systems: International Space Station PART for failure data, Vehicle Master Database (VMDB) for ORU & components, Maintenance & Analysis Data Set (MADS) for operation hours and other pertinent data, & Hardware History Retrieval System (HHRS) for unit weights. MaRS is populated using a Visual Basic Application. Once populated, the excel spreadsheet is comprised of information on ISS components including: operation hours, random/nonrandom failures, software/hardware failures, quantity, orbital replaceable units (ORU), date of placement, unit weight, frequency of part, etc. The motivation for creating such a database will be the development of a mass/reliability parametric model to estimate mass required for replacement parts. Once complete, engineers working on future space flight missions will have access a mean time to failures and on parts along with their mass, this will be used to make proper decisions for long duration space flight missions

Overview of the Systems Special Investigation Group investigation

NASA Technical Reports Server (NTRS)

Mason, James B.; Dursch, Harry; Edelman, Joel

1993-01-01

The Long Duration Exposure Facility (LDEF) carried a remarkable variety of electrical, mechanical, thermal, and optical systems, subsystems, and components. Nineteen of the fifty-seven experiments flown on LDEF contained functional systems that were active on-orbit. Almost all of the other experiments possessed at least a few specific components of interest to the Systems Special Investigation Group (Systems SIG), such as adhesives, seals, fasteners, optical components, and thermal blankets. Almost all top level functional testing of the active LDEF and experiment systems has been completed. Failure analysis of both LDEF hardware and individual experiments that failed to perform as designed has also been completed. Testing of system components and experimenter hardware of interest to the Systems SIG is ongoing. All available testing and analysis results were collected and integrated by the Systems SIG. An overview of our findings is provided. An LDEF Optical Experiment Database containing information for all 29 optical related experiments is also discussed.

Independent Orbiter Assessment (IOA): Analysis of the Orbiter Experiment (OEX) subsystem

NASA Technical Reports Server (NTRS)

Compton, J. M.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Experiments hardware. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. The Orbiter Experiments (OEX) Program consists of a multiple set of experiments for the purpose of gathering environmental and aerodynamic data to develop more accurate ground models for Shuttle performance and to facilitate the design of future spacecraft. This assessment only addresses currently manifested experiments and their support systems. Specifically this list consists of: Shuttle Entry Air Data System (SEADS); Shuttle Upper Atmosphere Mass Spectrometer (SUMS); Forward Fuselage Support System for OEX (FFSSO); Shuttle Infrared Laced Temperature Sensor (SILTS); Aerodynamic Coefficient Identification Package (ACIP); and Support System for OEX (SSO). There are only two potential critical items for the OEX, since the experiments only gather data for analysis post mission and are totally independent systems except for power. Failure of any experiment component usually only causes a loss of experiment data and in no way jeopardizes the crew or mission.

Failure Analysis Results and Corrective Actions Implemented for the Extravehicular Mobility Unit 3011 Water in the Helmet Mishap

NASA Technical Reports Server (NTRS)

Steele, John; Metselaar, Carol; Peyton, Barbara; Rector, Tony; Rossato, Robert; Macias, Brian; Weigel, Dana; Holder, Don

2015-01-01

Water entered the Extravehicular Mobility Unit (EMU) helmet during extravehicular activity (EVA) no. 23 aboard the International Space Station on July 16, 2013, resulting in the termination of the EVA approximately 1 hour after it began. It was estimated that 1.5 liters of water had migrated up the ventilation loop into the helmet, adversely impacting the astronaut's hearing, vision, and verbal communication. Subsequent on-board testing and ground-based test, tear-down, and evaluation of the affected EMU hardware components determined that the proximate cause of the mishap was blockage of all water separator drum holes with a mixture of silica and silicates. The blockages caused a failure of the water separator degassing function, which resulted in EMU cooling water spilling into the ventilation loop, migrating around the circulating fan, and ultimately pushing into the helmet. The root cause of the failure was determined to be ground-processing shortcomings of the Airlock Cooling Loop Recovery (ALCLR) Ion Filter Beds, which led to various levels of contaminants being introduced into the filters before they left the ground. Those contaminants were thereafter introduced into the EMU hardware on-orbit during ALCLR scrubbing operations. This paper summarizes the failure analysis results along with identified process, hardware, and operational corrective actions that were implemented as a result of findings from this investigation.

Failure Analysis Results and Corrective Actions Implemented for the EMU 3011 Water in the Helmet Mishap

NASA Technical Reports Server (NTRS)

Steele, John; Metselaar, Carol; Peyton, Barbara; Rector, Tony; Rossato, Robert; Macias, Brian; Weigel, Dana; Holder, Don

2015-01-01

During EVA (Extravehicular Activity) No. 23 aboard the ISS (International Space Station) on 07/16/2013 water entered the EMU (Extravehicular Mobility Unit) helmet resulting in the termination of the EVA (Extravehicular Activity) approximately 1-hour after it began. It was estimated that 1.5-L of water had migrated up the ventilation loop into the helmet, adversely impacting the astronauts hearing, vision and verbal communication. Subsequent on-board testing and ground-based TT and E (Test, Tear-down and Evaluation) of the affected EMU hardware components led to the determination that the proximate cause of the mishap was blockage of all water separator drum holes with a mixture of silica and silicates. The blockages caused a failure of the water separator function which resulted in EMU cooling water spilling into the ventilation loop, around the circulating fan, and ultimately pushing into the helmet. The root cause of the failure was determined to be ground-processing short-comings of the ALCLR (Airlock Cooling Loop Recovery) Ion Filter Beds which led to various levels of contaminants being introduced into the Filters before they left the ground. Those contaminants were thereafter introduced into the EMU hardware on-orbit during ALCLR scrubbing operations. This paper summarizes the failure analysis results along with identified process, hardware and operational corrective actions that were implemented as a result of findings from this investigation.

Mass and Reliability Source (MaRS) Database

NASA Technical Reports Server (NTRS)

Valdenegro, Wladimir

2017-01-01

The Mass and Reliability Source (MaRS) Database consolidates components mass and reliability data for all Oribital Replacement Units (ORU) on the International Space Station (ISS) into a single database. It was created to help engineers develop a parametric model that relates hardware mass and reliability. MaRS supplies relevant failure data at the lowest possible component level while providing support for risk, reliability, and logistics analysis. Random-failure data is usually linked to the ORU assembly. MaRS uses this data to identify and display the lowest possible component failure level. As seen in Figure 1, the failure point is identified to the lowest level: Component 2.1. This is useful for efficient planning of spare supplies, supporting long duration crewed missions, allowing quicker trade studies, and streamlining diagnostic processes. MaRS is composed of information from various databases: MADS (operating hours), VMDB (indentured part lists), and ISS PART (failure data). This information is organized in Microsoft Excel and accessed through a program made in Microsoft Access (Figure 2). The focus of the Fall 2017 internship tour was to identify the components that were the root cause of failure from the given random-failure data, develop a taxonomy for the database, and attach material headings to the component list. Secondary objectives included verifying the integrity of the data in MaRS, eliminating any part discrepancies, and generating documentation for future reference. Due to the nature of the random-failure data, data mining had to be done manually without the assistance of an automated program to ensure positive identification.

Shuttle payload vibroacoustic test plan evaluation. Free flyer payload applications and sortie payload parametric variations

NASA Technical Reports Server (NTRS)

Stahle, C. V.; Gongloff, H. R.

1977-01-01

A preliminary assessment of vibroacoustic test plan optimization for free flyer STS payloads is presented and the effects on alternate test plans for Spacelab sortie payloads number of missions are also examined. The component vibration failure probability and the number of components in the housekeeping subassemblies are provided. Decision models are used to evaluate the cost effectiveness of seven alternate test plans using protoflight hardware.

A Report on Simulation-Driven Reliability and Failure Analysis of Large-Scale Storage Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wan, Lipeng; Wang, Feiyi; Oral, H. Sarp

High-performance computing (HPC) storage systems provide data availability and reliability using various hardware and software fault tolerance techniques. Usually, reliability and availability are calculated at the subsystem or component level using limited metrics such as, mean time to failure (MTTF) or mean time to data loss (MTTDL). This often means settling on simple and disconnected failure models (such as exponential failure rate) to achieve tractable and close-formed solutions. However, such models have been shown to be insufficient in assessing end-to-end storage system reliability and availability. We propose a generic simulation framework aimed at analyzing the reliability and availability of storagemore » systems at scale, and investigating what-if scenarios. The framework is designed for an end-to-end storage system, accommodating the various components and subsystems, their interconnections, failure patterns and propagation, and performs dependency analysis to capture a wide-range of failure cases. We evaluate the framework against a large-scale storage system that is in production and analyze its failure projections toward and beyond the end of lifecycle. We also examine the potential operational impact by studying how different types of components affect the overall system reliability and availability, and present the preliminary results« less

Evaluating the Performance of the NASA LaRC CMF Motion Base Safety Devices

NASA Technical Reports Server (NTRS)

Gupton, Lawrence E.; Bryant, Richard B., Jr.; Carrelli, David J.

2006-01-01

This paper describes the initial measured performance results of the previously documented NASA Langley Research Center (LaRC) Cockpit Motion Facility (CMF) motion base hardware safety devices. These safety systems are required to prevent excessive accelerations that could injure personnel and damage simulator cockpits or the motion base structure. Excessive accelerations may be caused by erroneous commands or hardware failures driving an actuator to the end of its travel at high velocity, stepping a servo valve, or instantly reversing servo direction. Such commands may result from single order failures of electrical or hydraulic components within the control system itself, or from aggressive or improper cueing commands from the host simulation computer. The safety systems must mitigate these high acceleration events while minimizing the negative performance impacts. The system accomplishes this by controlling the rate of change of valve signals to limit excessive commanded accelerations. It also aids hydraulic cushion performance by limiting valve command authority as the actuator approaches its end of travel. The design takes advantage of inherent motion base hydraulic characteristics to implement all safety features using hardware only solutions.

Implementing a Microcontroller Watchdog with a Field-Programmable Gate Array (FPGA)

NASA Technical Reports Server (NTRS)

Straka, Bartholomew

2013-01-01

Reliability is crucial to safety. Redundancy of important system components greatly enhances reliability and hence safety. Field-Programmable Gate Arrays (FPGAs) are useful for monitoring systems and handling the logic necessary to keep them running with minimal interruption when individual components fail. A complete microcontroller watchdog with logic for failure handling can be implemented in a hardware description language (HDL.). HDL-based designs are vendor-independent and can be used on many FPGAs with low overhead.

The Large Synoptic Survey Telescope

NASA Astrophysics Data System (ADS)

Axelrod, T. S.

2006-07-01

The Large Synoptic Survey Telescope (LSST) is an 8.4 meter telescope with a 10 square degree field degree field and a 3 Gigapixel imager, planned to be on-sky in 2012. It is a dedicated all-sky survey instrument, with several complementary science missions. These include understanding dark energy through weak lensing and supernovae; exploring transients and variable objects; creating and maintaining a solar system map, with particular emphasis on potentially hazardous objects; and increasing the precision with which we understand the structure of the Milky Way. The instrument operates continuously at a rapid cadence, repetitively scanning the visible sky every few nights. The data flow rates from LSST are larger than those from current surveys by roughly a factor of 1000: A few GB/night are typical today. LSST will deliver a few TB/night. From a computing hardware perspective, this factor of 1000 can be dealt with easily in 2012. The major issues in designing the LSST data management system arise from the fact that the number of people available to critically examine the data will not grow from current levels. This has a number of implications. For example, every large imaging survey today is resigned to the fact that their image reduction pipelines fail at some significant rate. Many of these failures are dealt with by rerunning the reduction pipeline under human supervision, with carefully ``tweaked'' parameters to deal with the original problem. For LSST, this will no longer be feasible. The problem is compounded by the fact that the processing must of necessity occur on clusters with large numbers of CPU's and disk drives, and with some components connected by long-haul networks. This inevitably results in a significant rate of hardware component failures, which can easily lead to further software failures. Both hardware and software failures must be seen as a routine fact of life rather than rare exceptions to normality.

Model-OA wind turbine generator - Failure modes and effects analysis

NASA Technical Reports Server (NTRS)

Klein, William E.; Lali, Vincent R.

1990-01-01

The results failure modes and effects analysis (FMEA) conducted for wind-turbine generators are presented. The FMEA was performed for the functional modes of each system, subsystem, or component. The single-point failures were eliminated for most of the systems. The blade system was the only exception. The qualitative probability of a blade separating was estimated at level D-remote. Many changes were made to the hardware as a result of this analysis. The most significant change was the addition of the safety system. Operational experience and need to improve machine availability have resulted in subsequent changes to the various systems, which are also reflected in this FMEA.

Cause and Effects of Fluorocarbon Degradation in Electronics and Opto-Electronic Systems

NASA Technical Reports Server (NTRS)

Predmore, Roamer E.; Canham, John S.

2002-01-01

Trace degradation of fluorocarbon or halocarbon materials must be addressed in their application in sensitive systems. As the dimensions and/or tolerances of components in a system decrease, the sensitivity of the system to trace fluorocarbon or halocarbon degradation products increases. Trace quantities of highly reactive degradation products from fluorocarbons have caused a number of failures of flight hardware. It is of utmost importance that the risk of system failure, resulting from trace amounts of reactive fluorocarbon degradation products be addressed in designs containing fluorocarbon or halocarbon materials. Thermal, electrical, and mechanical energy input into the system can multiply the risk of failure.

Independent Orbiter Assessment (IOA): Assessment of the electrical power generation/power reactant storage and distribution subsystem FMEA/CIL

NASA Technical Reports Server (NTRS)

Ames, B. E.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) is presented. The IOA effort first completed an analysis of the Electrical Power Generation/Power Reactant Storage and Distribution (EPG/PRSD) subsystem hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baselines with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. The results of that comparison are documented for the Orbiter EPG/PRSD hardware. The comparison produced agreement on all but 27 FMEAs and 9 CIL items. The discrepancy between the number of IOA findings and NASA FMEAs can be partially explained by the different approaches used by IOA and NASA to group failure modes together to form one FMEA. Also, several IOA items represented inner tank components and ground operations failure modes which were not in the NASA baseline.

Independent Orbiter Assessment (IOA): Assessment of the life support and airlock support systems, volume 1

NASA Technical Reports Server (NTRS)

Arbet, J. D.; Duffy, R. E.; Barickman, K.; Saiidi, M. J.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Life Support and Airlock Support Systems (LSS and ALSS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. The discrepancies were flagged for potential future resolution. This report documents the results of that comparison for the Orbiter LSS and ALSS hardware. The IOA product for the LSS and ALSS analysis consisted of 511 failure mode worksheets that resulted in 140 potential critical items. Comparison was made to the NASA baseline which consisted of 456 FMEAs and 101 CIL items. The IOA analysis identified 39 failure modes, 6 of which were classified as CIL items, for components not covered by the NASA FMEAs. It was recommended that these failure modes be added to the NASA FMEA baseline. The overall assessment produced agreement on all but 301 FMEAs which caused differences in 111 CIL items.

More About Software for No-Loss Computing

NASA Technical Reports Server (NTRS)

Edmonds, Iarina

2007-01-01

A document presents some additional information on the subject matter of "Integrated Hardware and Software for No- Loss Computing" (NPO-42554), which appears elsewhere in this issue of NASA Tech Briefs. To recapitulate: The hardware and software designs of a developmental parallel computing system are integrated to effectuate a concept of no-loss computing (NLC). The system is designed to reconfigure an application program such that it can be monitored in real time and further reconfigured to continue a computation in the event of failure of one of the computers. The design provides for (1) a distributed class of NLC computation agents, denoted introspection agents, that effects hierarchical detection of anomalies; (2) enhancement of the compiler of the parallel computing system to cause generation of state vectors that can be used to continue a computation in the event of a failure; and (3) activation of a recovery component when an anomaly is detected.

Orbiter subsystem hardware/software interaction analysis. Volume 8: Forward reaction control system

NASA Technical Reports Server (NTRS)

Becker, D. D.

1980-01-01

The results of the orbiter hardware/software interaction analysis for the AFT reaction control system are presented. The interaction between hardware failure modes and software are examined in order to identify associated issues and risks. All orbiter subsystems and interfacing program elements which interact with the orbiter computer flight software are analyzed. The failure modes identified in the subsystem/element failure mode and effects analysis are discussed.

Failure Diagnosis for the Holdup Tank System via ISFA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Huijuan; Bragg-Sitton, Shannon; Smidts, Carol

This paper discusses the use of the integrated system failure analysis (ISFA) technique for fault diagnosis for the holdup tank system. ISFA is a simulation-based, qualitative and integrated approach used to study fault propagation in systems containing both hardware and software subsystems. The holdup tank system consists of a tank containing a fluid whose level is controlled by an inlet valve and an outlet valve. We introduce the component and functional models of the system, quantify the main parameters and simulate possible failure-propagation paths based on the fault propagation approach, ISFA. The results show that most component failures in themore » holdup tank system can be identified clearly and that ISFA is viable as a technique for fault diagnosis. Since ISFA is a qualitative technique that can be used in the very early stages of system design, this case study provides indications that it can be used early to study design aspects that relate to robustness and fault tolerance.« less

Independent Orbiter Assessment (IOA): Assessment of the mechanical actuation subsystem, volume 2

NASA Technical Reports Server (NTRS)

Bradway, M. W.; Slaughter, W. T.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine draft failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline that was available. A resolution of each discrepancy from the comparison was provided through additional analysis as required. These discrepancies were flagged as issues, and recommendations were made based on the FMEA data available at the time. This report documents the results of that comparison for the Orbiter Mechanical Actuation System (MAS) hardware. Specifically, the MAS hardware consists of the following components: Air Data Probe (ADP); Elevon Seal Panel (ESP); External Tank Umbilical (ETU); Ku-Band Deploy (KBD); Payload Bay Doors (PBD); Payload Bay Radiators (PBR); Personnel Hatches (PH); Vent Door Mechanism (VDM); and Startracker Door Mechanism (SDM). Criticality was assigned based upon the severity of the effect for each failure mode. Volume 2 continues the presentation of IOA analysis worksheets and contains the potential critical items list, detailed analysis, and NASA FMEA/CIL to IOA worksheet cross reference and recommendations.

Development of KSC program for investigating and generating field failure rates. Volume 1: Summary and overview

NASA Technical Reports Server (NTRS)

Bean, E. E.; Bloomquist, C. E.

1972-01-01

A summary of the KSC program for investigating the reliability aspects of the ground support activities is presented. An analysis of unsatisfactory condition reports (RC), and the generation of reliability assessment of components based on the URC are discussed along with the design considerations for attaining reliable real time hardware/software configurations.

Independent Orbiter Assessment (IOA): Analysis of the purge, vent and drain subsystem

NASA Technical Reports Server (NTRS)

Bynum, M. C., III

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter PV and D (Purge, Vent and Drain) Subsystem hardware. The PV and D Subsystem controls the environment of unpressurized compartments and window cavities, senses hazardous gases, and purges Orbiter/ET Disconnect. The subsystem is divided into six systems: Purge System (controls the environment of unpressurized structural compartments); Vent System (controls the pressure of unpressurized compartments); Drain System (removes water from unpressurized compartments); Hazardous Gas Detection System (HGDS) (monitors hazardous gas concentrations); Window Cavity Conditioning System (WCCS) (maintains clear windows and provides pressure control of the window cavities); and External Tank/Orbiter Disconnect Purge System (prevents cryo-pumping/icing of disconnect hardware). Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Four of the sixty-two failure modes analyzed were determined as single failures which could result in the loss of crew or vehicle. A possible loss of mission could result if any of twelve single failures occurred. Two of the criticality 1/1 failures are in the Window Cavity Conditioning System (WCCS) outer window cavity, where leakage and/or restricted flow will cause failure to depressurize/repressurize the window cavity. Two criticality 1/1 failures represent leakage and/or restricted flow in the Orbiter/ET disconnect purge network which prevent cryopumping/icing of disconnect hardware. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode.

Fault tolerance in a supercomputer through dynamic repartitioning

DOEpatents

Chen, Dong; Coteus, Paul W.; Gara, Alan G.; Takken, Todd E.

2007-02-27

A multiprocessor, parallel computer is made tolerant to hardware failures by providing extra groups of redundant standby processors and by designing the system so that these extra groups of processors can be swapped with any group which experiences a hardware failure. This swapping can be under software control, thereby permitting the entire computer to sustain a hardware failure but, after swapping in the standby processors, to still appear to software as a pristine, fully functioning system.

Determining Component Probability using Problem Report Data for Ground Systems used in Manned Space Flight

NASA Technical Reports Server (NTRS)

Monaghan, Mark W.; Gillespie, Amanda M.

2013-01-01

During the shuttle era NASA utilized a failure reporting system called the Problem Reporting and Corrective Action (PRACA) it purpose was to identify and track system non-conformance. The PRACA system over the years evolved from a relatively nominal way to identify system problems to a very complex tracking and report generating data base. The PRACA system became the primary method to categorize any and all anomalies from corrosion to catastrophic failure. The systems documented in the PRACA system range from flight hardware to ground or facility support equipment. While the PRACA system is complex, it does possess all the failure modes, times of occurrence, length of system delay, parts repaired or replaced, and corrective action performed. The difficulty is mining the data then to utilize that data in order to estimate component, Line Replaceable Unit (LRU), and system reliability analysis metrics. In this paper, we identify a methodology to categorize qualitative data from the ground system PRACA data base for common ground or facility support equipment. Then utilizing a heuristic developed for review of the PRACA data determine what reports identify a credible failure. These data are the used to determine inter-arrival times to perform an estimation of a metric for repairable component-or LRU reliability. This analysis is used to determine failure modes of the equipment, determine the probability of the component failure mode, and support various quantitative differing techniques for performing repairable system analysis. The result is that an effective and concise estimate of components used in manned space flight operations. The advantage is the components or LRU's are evaluated in the same environment and condition that occurs during the launch process.

Field Programmable Gate Array Failure Rate Estimation Guidelines for Launch Vehicle Fault Tree Models

NASA Technical Reports Server (NTRS)

Al Hassan, Mohammad; Britton, Paul; Hatfield, Glen Spencer; Novack, Steven D.

2017-01-01

Today's launch vehicles complex electronic and avionics systems heavily utilize Field Programmable Gate Array (FPGA) integrated circuits (IC) for their superb speed and reconfiguration capabilities. Consequently, FPGAs are prevalent ICs in communication protocols such as MILSTD- 1553B and in control signal commands such as in solenoid valve actuations. This paper will identify reliability concerns and high level guidelines to estimate FPGA total failure rates in a launch vehicle application. The paper will discuss hardware, hardware description language, and radiation induced failures. The hardware contribution of the approach accounts for physical failures of the IC. The hardware description language portion will discuss the high level FPGA programming languages and software/code reliability growth. The radiation portion will discuss FPGA susceptibility to space environment radiation.

Independent Orbiter Assessment (IOA): Analysis of the orbiter main propulsion system

NASA Technical Reports Server (NTRS)

Mcnicoll, W. J.; Mcneely, M.; Holden, K. A.; Emmons, T. E.; Lowery, H. J.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbiter Main Propulsion System (MPS) hardware are documented. The Orbiter MPS consists of two subsystems: the Propellant Management Subsystem (PMS) and the Helium Subsystem. The PMS is a system of manifolds, distribution lines and valves by which the liquid propellants pass from the External Tank (ET) to the Space Shuttle Main Engines (SSMEs) and gaseous propellants pass from the SSMEs to the ET. The Helium Subsystem consists of a series of helium supply tanks and their associated regulators, check valves, distribution lines, and control valves. The Helium Subsystem supplies helium that is used within the SSMEs for inflight purges and provides pressure for actuation of SSME valves during emergency pneumatic shutdowns. The balance of the helium is used to provide pressure to operate the pneumatically actuated valves within the PMS. Each component was evaluated and analyzed for possible failure modes and effects. Criticalities were assigned based on the worst possible effect of each failure mode. Of the 690 failure modes analyzed, 349 were determined to be PCIs.

Independent Orbiter Assessment (IOA): Analysis of the instrumentation subsystem

NASA Technical Reports Server (NTRS)

Howard, B. S.

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Instrumentation Subsystem are documented. The Instrumentation Subsystem (SS) consists of transducers, signal conditioning equipment, pulse code modulation (PCM) encoding equipment, tape recorders, frequency division multiplexers, and timing equipment. For this analysis, the SS is broken into two major groupings: Operational Instrumentation (OI) equipment and Modular Auxiliary Data System (MADS) equipment. The OI equipment is required to acquire, condition, scale, digitize, interleave/multiplex, format, and distribute operational Orbiter and payload data and voice for display, recording, telemetry, and checkout. It also must provide accurate timing for time critical functions for crew and payload specialist use. The MADS provides additional instrumentation to measure and record selected pressure, temperature, strain, vibration, and event data for post-flight playback and analysis. MADS data is used to assess vehicle responses to the flight environment and to permit correlation of such data from flight to flight. The IOA analysis utilized available SS hardware drawings and schematics for identifying hardware assemblies and components and their interfaces. Criticality for each item was assigned on the basis of the worst-case effect of the failure modes identified.

An experimental evaluation of software redundancy as a strategy for improving reliability

NASA Technical Reports Server (NTRS)

Eckhardt, Dave E., Jr.; Caglayan, Alper K.; Knight, John C.; Lee, Larry D.; Mcallister, David F.; Vouk, Mladen A.; Kelly, John P. J.

1990-01-01

The strategy of using multiple versions of independently developed software as a means to tolerate residual software design faults is suggested by the success of hardware redundancy for tolerating hardware failures. Although, as generally accepted, the independence of hardware failures resulting from physical wearout can lead to substantial increases in reliability for redundant hardware structures, a similar conclusion is not immediate for software. The degree to which design faults are manifested as independent failures determines the effectiveness of redundancy as a method for improving software reliability. Interest in multi-version software centers on whether it provides an adequate measure of increased reliability to warrant its use in critical applications. The effectiveness of multi-version software is studied by comparing estimates of the failure probabilities of these systems with the failure probabilities of single versions. The estimates are obtained under a model of dependent failures and compared with estimates obtained when failures are assumed to be independent. The experimental results are based on twenty versions of an aerospace application developed and certified by sixty programmers from four universities. Descriptions of the application, development and certification processes, and operational evaluation are given together with an analysis of the twenty versions.

Structural health monitoring apparatus and methodology

NASA Technical Reports Server (NTRS)

Giurgiutiu, Victor (Inventor); Yu, Lingyu (Inventor); Bottai, Giola Santoni (Inventor)

2011-01-01

Disclosed is an apparatus and methodology for structural health monitoring (SHM) in which smart devices interrogate structural components to predict failure, expedite needed repairs, and thus increase the useful life of those components. Piezoelectric wafer active sensors (PWAS) are applied to or integrated with structural components and various data collected there from provide the ability to detect and locate cracking, corrosion, and disbanding through use of pitch-catch, pulse-echo, electro/mechanical impedance, and phased array technology. Stand alone hardware and an associated software program are provided that allow selection of multiple types of SHM investigations as well as multiple types of data analysis to perform a wholesome investigation of a structure.

Advanced information processing system: The Army fault tolerant architecture conceptual study. Volume 2: Army fault tolerant architecture design and analysis

NASA Technical Reports Server (NTRS)

Harper, R. E.; Alger, L. S.; Babikyan, C. A.; Butler, B. P.; Friend, S. A.; Ganska, R. J.; Lala, J. H.; Masotto, T. K.; Meyer, A. J.; Morton, D. P.

1992-01-01

Described here is the Army Fault Tolerant Architecture (AFTA) hardware architecture and components and the operating system. The architectural and operational theory of the AFTA Fault Tolerant Data Bus is discussed. The test and maintenance strategy developed for use in fielded AFTA installations is presented. An approach to be used in reducing the probability of AFTA failure due to common mode faults is described. Analytical models for AFTA performance, reliability, availability, life cycle cost, weight, power, and volume are developed. An approach is presented for using VHSIC Hardware Description Language (VHDL) to describe and design AFTA's developmental hardware. A plan is described for verifying and validating key AFTA concepts during the Dem/Val phase. Analytical models and partial mission requirements are used to generate AFTA configurations for the TF/TA/NOE and Ground Vehicle missions.

Model 0A wind turbine generator FMEA

NASA Technical Reports Server (NTRS)

Klein, William E.; Lalli, Vincent R.

1989-01-01

The results of Failure Modes and Effects Analysis (FMEA) conducted for the Wind Turbine Generators are presented. The FMEA was performed for the functional modes of each system, subsystem, or component. The single-point failures were eliminated for most of the systems. The blade system was the only exception. The qualitative probability of a blade separating was estimated at level D-remote. Many changes were made to the hardware as a result of this analysis. The most significant change was the addition of the safety system. Operational experience and need to improve machine availability have resulted in subsequent changes to the various systems which are also reflected in this FMEA.

Experimental and Analytical Investigation of Pressure Differentials for Clean and Loaded Wire Meshes Used in Zeolite Retention

NASA Technical Reports Server (NTRS)

Knox, James C.

2004-01-01

Following failure of the carbon dioxide removal assembly (CDRA) on the ISS, a CDRA teardown, test, and evaluation (TT&E) effort found that the sorbent material was not retained as intended by the packed beds and that presence of the sorbent in the check valve and selector valve was the cause of the failure of these components. This paper documents the development of design data for an in-line filter element. The purpose of the in-line filter is to provide temporary protection for on-orbit CDRA hardware until the bed retainment system can be redesigned and replaced.

Independent Orbiter Assessment (IOA): Analysis of the displays and controls subsystem

NASA Technical Reports Server (NTRS)

Trahan, W. H.; Prust, E. E.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Displays and Controls (D and C) subsystem hardware. The function of the D and C hardware is to provide the crew with the monitor, command, and control capabilities required for management of all normal and contingency mission and flight operations. The D and C hardware for which failure modes analysis was performed consists of the following: Acceleration Indicator (G-METER); Head Up Display (HUD); Display Driver Unit (DDU); Alpha/Mach Indicator (AMI); Horizontal Situation Indicator (HSI); Attitude Director Indicator (ADI); Propellant Quantity Indicator (PQI); Surface Position Indicator (SPI); Altitude/Vertical Velocity Indicator (AVVI); Caution and Warning Assembly (CWA); Annunciator Control Assembly (ACA); Event Timer (ET); Mission Timer (MT); Interior Lighting; and Exterior Lighting. Each hardware item was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode.

An Alternative Method Of Specifying Shock Test Criteria

NASA Technical Reports Server (NTRS)

Ferebee, R. C.; Clayton, J.; Alldredge, D.; Irvine, T.

2008-01-01

Shock testing of aerospace vehicle hardware has presented many challenges over the years due to the high magnitude and short duration of the specifications. Recently, component structural failures have occurred during testing that have not manifested themselves on over 200 Space Shuttle solid rocket booster (SRB) flights (two boosters per flight). It is suspected that the method of specifying shock test criteria may be leaving important information out of the test process. The traditional test criteria specification, the shock response spectrum, can be duplicated by any number of waveforms that may not resemble the actual flight test recorded time history. One method of overcoming this limitation is described herein, which may prove useful for qualifying hardware for the upcoming Constellation Program.

Control System Architectures, Technologies and Concepts for Near Term and Future Human Exploration of Space

NASA Technical Reports Server (NTRS)

Boulanger, Richard; Overland, David

2004-01-01

Technologies that facilitate the design and control of complex, hybrid, and resource-constrained systems are examined. This paper focuses on design methodologies, and system architectures, not on specific control methods that may be applied to life support subsystems. Honeywell and Boeing have estimated that 60-80Y0 of the effort in developing complex control systems is software development, and only 20-40% is control system development. It has also been shown that large software projects have failure rates of as high as 50-65%. Concepts discussed include the Unified Modeling Language (UML) and design patterns with the goal of creating a self-improving, self-documenting system design process. Successful architectures for control must not only facilitate hardware to software integration, but must also reconcile continuously changing software with much less frequently changing hardware. These architectures rely on software modules or components to facilitate change. Architecting such systems for change leverages the interfaces between these modules or components.

Integrated tracking of components by engineering and logistics utilizing logistics asset tracking system

NASA Technical Reports Server (NTRS)

Renfroe, Michael B.; Mcdonald, Edward J.; Bradshaw, Kimberly

1988-01-01

The Logistics Asset Tracking System (LATS) devised by NASA contains data on Space Shuttle LRUs that are daily updated to reflect such LRU status changes as repair due to failure or modification due to changing engineering requirements. The implementation of LATS has substantially increased personnel responsiveness, preventing costly delays in Space Shuttle processing and obviating hardware cannibalization. An evaluation is presented of LATS achievements in the direction of an integrated logistical support posture.

Fracture - An Unforgiving Failure Mode

NASA Technical Reports Server (NTRS)

Goodin, James Ronald

2006-01-01

During the 2005 Conference for the Advancement for Space Safety, after a typical presentation of safety tools, a Russian in the audience simply asked, "How does that affect the hardware?" Having participated in several International System Safety Conferences, I recalled that most attention is dedicated to safety tools and little, if any, to hardware. The intent of this paper on the hazard of fracture and failure modes associated with fracture is my attempt to draw attention to the grass roots of system safety - improving hardware robustness and resilience.

UAS-Systems Integration, Validation, and Diagnostics Simulation Capability

NASA Technical Reports Server (NTRS)

Buttrill, Catherine W.; Verstynen, Harry A.

2014-01-01

As part of the Phase 1 efforts of NASA's UAS-in-the-NAS Project a task was initiated to explore the merits of developing a system simulation capability for UAS to address airworthiness certification requirements. The core of the capability would be a software representation of an unmanned vehicle, including all of the relevant avionics and flight control system components. The specific system elements could be replaced with hardware representations to provide Hardware-in-the-Loop (HWITL) test and evaluation capability. The UAS Systems Integration and Validation Laboratory (UAS-SIVL) was created to provide a UAS-systems integration, validation, and diagnostics hardware-in-the-loop simulation capability. This paper discusses how SIVL provides a robust and flexible simulation framework that permits the study of failure modes, effects, propagation paths, criticality, and mitigation strategies to help develop safety, reliability, and design data that can assist with the development of certification standards, means of compliance, and design best practices for civil UAS.

Independent Orbiter Assessment (IOA): Analysis of the electrical power distribution and control subsystem, volume 1

NASA Technical Reports Server (NTRS)

Schmeckpeper, K. R.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Electrical Power Distribution and Control (EPD and C) hardware. The EPD and C hardware performs the functions of distributing, sensing, and controlling 28 volt DC power and of inverting, distributing, sensing, and controlling 117 volt 400 Hz AC power to all Orbiter subsystems from the three fuel cells in the Electrical Power Generation (EPG) subsystem. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Of the 1671 failure modes analyzed, 9 single failures were determined to result in loss of crew or vehicle. Three single failures unique to intact abort were determined to result in possible loss of the crew or vehicle. A possible loss of mission could result if any of 136 single failures occurred. Six of the criticality 1/1 failures are in two rotary and two pushbutton switches that control External Tank and Solid Rocket Booster separation. The other 6 criticality 1/1 failures are fuses, one each per Aft Power Control Assembly (APCA) 4, 5, and 6 and one each per Forward Power Control Assembly (FPCA) 1, 2, and 3, that supply power to certain Main Propulsion System (MPS) valves and Forward Reaction Control System (RCS) circuits.

SILHIL Replication of Electric Aircraft Powertrain Dynamics and Inner-Loop Control for V&V of System Health Management Routines

NASA Technical Reports Server (NTRS)

Bole, Brian; Teubert, Christopher Allen; Cuong Chi, Quach; Hogge, Edward; Vazquez, Sixto; Goebel, Kai; George, Vachtsevanos

2013-01-01

Software-in-the-loop and Hardware-in-the-loop testing of failure prognostics and decision making tools for aircraft systems will facilitate more comprehensive and cost-effective testing than what is practical to conduct with flight tests. A framework is described for the offline recreation of dynamic loads on simulated or physical aircraft powertrain components based on a real-time simulation of airframe dynamics running on a flight simulator, an inner-loop flight control policy executed by either an autopilot routine or a human pilot, and a supervisory fault management control policy. The creation of an offline framework for verifying and validating supervisory failure prognostics and decision making routines is described for the example of battery charge depletion failure scenarios onboard a prototype electric unmanned aerial vehicle.

76 FR 11511 - In the Matter of Certain Set-Top Boxes, and Hardware and Software Components Thereof; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-02

... Hardware and Software Components Thereof; Notice of Investigation AGENCY: U.S. International Trade... boxes, and hardware and software components thereof by reason of infringement of certain claims of U.S... after importation of certain set-top boxes, and hardware and software components thereof that infringe...

Reliability Growth in Space Life Support Systems

NASA Technical Reports Server (NTRS)

Jones, Harry W.

2014-01-01

A hardware system's failure rate often increases over time due to wear and aging, but not always. Some systems instead show reliability growth, a decreasing failure rate with time, due to effective failure analysis and remedial hardware upgrades. Reliability grows when failure causes are removed by improved design. A mathematical reliability growth model allows the reliability growth rate to be computed from the failure data. The space shuttle was extensively maintained, refurbished, and upgraded after each flight and it experienced significant reliability growth during its operational life. In contrast, the International Space Station (ISS) is much more difficult to maintain and upgrade and its failure rate has been constant over time. The ISS Carbon Dioxide Removal Assembly (CDRA) reliability has slightly decreased. Failures on ISS and with the ISS CDRA continue to be a challenge.

Evaluation of methods for determining hardware projected life

NASA Technical Reports Server (NTRS)

1971-01-01

An investigation of existing methods of predicting hardware life is summarized by reviewing programs having long life requirements, current research efforts on long life problems, and technical papers reporting work on life predicting techniques. The results indicate that there are no accurate quantitative means to predict hardware life for system level hardware. The effectiveness of test programs and the cause of hardware failures is considered.

Effect of system workload on operating system reliability - A study on IBM 3081

NASA Technical Reports Server (NTRS)

Iyer, R. K.; Rossetti, D. J.

1985-01-01

This paper presents an analysis of operating system failures on an IBM 3081 running VM/SP. Three broad categories of software failures are found: error handling, program control or logic, and hardware related; it is found that more than 25 percent of software failures occur in the hardware/software interface. Measurements show that results on software reliability cannot be considered representative unless the system workload is taken into account. The overall CPU execution rate, although measured to be close to 100 percent most of the time, is not found to correlate strongly with the occurrence of failures. Possible reasons for the observed workload failure dependency, based on detailed investigations of the failure data, are discussed.

From experiment to design -- Fault characterization and detection in parallel computer systems using computational accelerators

NASA Astrophysics Data System (ADS)

Yim, Keun Soo

This dissertation summarizes experimental validation and co-design studies conducted to optimize the fault detection capabilities and overheads in hybrid computer systems (e.g., using CPUs and Graphics Processing Units, or GPUs), and consequently to improve the scalability of parallel computer systems using computational accelerators. The experimental validation studies were conducted to help us understand the failure characteristics of CPU-GPU hybrid computer systems under various types of hardware faults. The main characterization targets were faults that are difficult to detect and/or recover from, e.g., faults that cause long latency failures (Ch. 3), faults in dynamically allocated resources (Ch. 4), faults in GPUs (Ch. 5), faults in MPI programs (Ch. 6), and microarchitecture-level faults with specific timing features (Ch. 7). The co-design studies were based on the characterization results. One of the co-designed systems has a set of source-to-source translators that customize and strategically place error detectors in the source code of target GPU programs (Ch. 5). Another co-designed system uses an extension card to learn the normal behavioral and semantic execution patterns of message-passing processes executing on CPUs, and to detect abnormal behaviors of those parallel processes (Ch. 6). The third co-designed system is a co-processor that has a set of new instructions in order to support software-implemented fault detection techniques (Ch. 7). The work described in this dissertation gains more importance because heterogeneous processors have become an essential component of state-of-the-art supercomputers. GPUs were used in three of the five fastest supercomputers that were operating in 2011. Our work included comprehensive fault characterization studies in CPU-GPU hybrid computers. In CPUs, we monitored the target systems for a long period of time after injecting faults (a temporally comprehensive experiment), and injected faults into various types of program states that included dynamically allocated memory (to be spatially comprehensive). In GPUs, we used fault injection studies to demonstrate the importance of detecting silent data corruption (SDC) errors that are mainly due to the lack of fine-grained protections and the massive use of fault-insensitive data. This dissertation also presents transparent fault tolerance frameworks and techniques that are directly applicable to hybrid computers built using only commercial off-the-shelf hardware components. This dissertation shows that by developing understanding of the failure characteristics and error propagation paths of target programs, we were able to create fault tolerance frameworks and techniques that can quickly detect and recover from hardware faults with low performance and hardware overheads.

Advanced Gas Turbine (AGT) Technology Project

NASA Technical Reports Server (NTRS)

1986-01-01

Engine testing, ceramic component fabrication and evaluation, component performance rig testing, and analytical studies comprised AGT 100 activities during the 1985 year. Ten experimental assemblies (builds) were evaluated using two engines. Accrued operating time was 120 hr of burning and 170 hr total, bringing cumulative total operating time to 395 hr, all devoid of major failures. Tests identified the generator seals as the primary working fluid leakage sources. Power transfer clutch operation was demonstrated. An alpha SiC gasifier rotor engine test resulted in blade tip failures. Recurring case vibration and shaft whip have limited gasifier shaft speeds to 84%. Ceramic components successfully engine tested now include the SiC scroll assembly, Si3N3 turbine rotor, combustor assembly, regenerator disk bulkhead, turbine vanes, piston rings, and couplings. A compressor shroud design change to reduce heat recirculation back to the inlet was executed. Ceramic components activity continues to focus on the development of state-of-the-art material strength characteristics in full-scale engine hardware. Fiber reinforced glass-ceramic composite turbine (inner) backplates were fabricated by Corning Glass Works. The BMAS/III material performed well in engine testing. Backplates of MAS material have not been engine tested.

High Energy Failure Containment for Spacecraft

NASA Technical Reports Server (NTRS)

Pektas, Pete; Baker, Christopher

2011-01-01

Objective: The objective of this paper will be to investigate advancements and any commonality between spacecraft debris containment and the improvements being made in ballistic protection. Scope: This paper will focus on cross application of protection devices and methods, and how they relate to protecting humans from failures in spacecraft. The potential gain is to reduce the risk associated with hardware failure, while decreasing the weight and size of energy containment methods currently being used by the government and commercial industry. Method of Approach: This paper will examine testing that has already been accomplished in regards to the failure of high energy rotating hardware and compare it to advancements in ballistic protection. Examples are: DOT research and testing of turbine containment as documented in DOT/FAA/AR-96/110, DOT/FAA/AR-97/82, DOT/FAA/AR-98/22. It will also look at work accomplished by companies such as ApNano and IBD Deisenroth in the development of nano ceramics and nanometric steels. Other forms of energy absorbent materials and composites will also be considered and discussed. New Advances in State of the Art: There have been numerous advances in technology in regards to high energy debris containment and in the similar field of ballistic protection. This paper will discuss methods such as using impregnated or dry Kevlar, ceramic, and nano-technology which have been successfully tested but are yet to be utilized in spacecraft. Reports on tungsten disulfide nanotubes claim that they are 4-5 times stronger than steel and reports vary about the magnitude increase over Kevlar, but it appears to be somewhere in the range of 2-6 times stronger. This technology could also have applications in the protection of pressure vessels, motor housings, and hydraulic component failures.

Effect of Joule heating and current crowding on electromigration in mobile technology

NASA Astrophysics Data System (ADS)

Tu, K. N.; Liu, Yingxia; Li, Menglu

2017-03-01

In the present era of big data and internet of things, the use of microelectronic products in all aspects of our life is manifested by the ubiquitous presence of mobile devices as i-phones and wearable i-products. These devices are facing the need for higher power and greater functionality applications such as in i-health, yet they are limited by physical size. At the moment, software (Apps) is much ahead of hardware in mobile technology. To advance hardware, the end of Moore's law in two-dimensional integrated circuits can be extended by three-dimensional integrated circuits (3D ICs). The concept of 3D ICs has been with us for more than ten years. The challenge in 3D IC technology is dense packing by using both vertical and horizontal interconnections. Mass production of 3D IC devices is behind schedule due to cost because of low yield and uncertain reliability. Joule heating is serious in a dense structure because of heat generation and dissipation. A change of reliability paradigm has advanced from failure at a specific circuit component to failure at a system level weak-link. Currently, the electronic industry is introducing 3D IC devices in mainframe computers, where cost is not an issue, for the purpose of collecting field data of failure, especially the effect of Joule heating and current crowding on electromigration. This review will concentrate on the positive feedback between Joule heating and electromigration, resulting in an accelerated system level weak-link failure. A new driving force of electromigration, the electric potential gradient force due to current crowding, will be reviewed critically. The induced failure tends to occur in the low current density region.

Evaluation of control parameters for Spray-In-Air (SIA) aqueous cleaning for shuttle RSRM hardware

NASA Technical Reports Server (NTRS)

Davis, S. J.; Deweese, C. D.

1995-01-01

HD-2 grease is deliberately applied to Shuttle Redesigned Solid Rocket Motor (RSRM) D6AC steel hardware parts as a temporary protective coating for storage and shipping. This HD-2 grease is the most common form of surface contamination on RSRM hardware and must be removed prior to subsequent surface treatment. Failure to achieve an acceptable level of cleanliness (HD-2 calcium grease removal) is a common cause of defect incidence. Common failures from ineffective cleaning include poor adhesion of surface coatings, reduced bond performance of structural adhesives, and failure to pass cleanliness inspection standards. The RSRM hardware is currently cleaned and refurbished using methyl chloroform (1,1,1-trichloroethane). This chlorinated solvent is mandated for elimination due to its ozone depleting characteristics. This report describes an experimental study of an aqueous cleaning system (which uses Brulin 815 GD) as a replacement for methyl chloroform. Evaluation of process control parameters for this cleaner are discussed as well as cleaning mechanisms for a spray-in-air process.

Extraction-Separation Performance and Dynamic Modeling of Orion Test Vehicles with Adams Simulation: 3rd Edition

NASA Technical Reports Server (NTRS)

Varela, Jose G.; Reddy, Satish; Moeller, Enrique; Anderson, Keith

2017-01-01

NASA's Orion Capsule Parachute Assembly System (CPAS) Project is now in the qualification phase of testing, and the Adams simulation has continued to evolve to model the complex dynamics experienced during the test article extraction and separation phases of flight. The ability to initiate tests near the upper altitude limit of the Orion parachute deployment envelope requires extractions from the aircraft at 35,000 ft-MSL. Engineering development phase testing of the Parachute Test Vehicle (PTV) carried by the Carriage Platform Separation System (CPSS) at altitude resulted in test support equipment hardware failures due to increased energy caused by higher true airspeeds. As a result, hardware modifications became a necessity requiring ground static testing of the textile components to be conducted and a new ground dynamic test of the extraction system to be devised. Force-displacement curves from static tests were incorporated into the Adams simulations, allowing prediction of loads, velocities and margins encountered during both flight and ground dynamic tests. The Adams simulation was then further refined by fine tuning the damping terms to match the peak loads recorded in the ground dynamic tests. The failure observed in flight testing was successfully replicated in ground testing and true safety margins of the textile components were revealed. A multi-loop energy modulator was then incorporated into the system level Adams simulation model and the effect on improving test margins be properly evaluated leading to high confidence ground verification testing of the final design solution.

Intelligent Hardware-Enabled Sensor and Software Safety and Health Management for Autonomous UAS

NASA Technical Reports Server (NTRS)

Rozier, Kristin Y.; Schumann, Johann; Ippolito, Corey

2015-01-01

Unmanned Aerial Systems (UAS) can only be deployed if they can effectively complete their mission and respond to failures and uncertain environmental conditions while maintaining safety with respect to other aircraft as well as humans and property on the ground. We propose to design a real-time, onboard system health management (SHM) capability to continuously monitor essential system components such as sensors, software, and hardware systems for detection and diagnosis of failures and violations of safety or performance rules during the ight of a UAS. Our approach to SHM is three-pronged, providing: (1) real-time monitoring of sensor and software signals; (2) signal analysis, preprocessing, and advanced on-the- y temporal and Bayesian probabilistic fault diagnosis; (3) an unobtrusive, lightweight, read-only, low-power hardware realization using Field Programmable Gate Arrays (FPGAs) in order to avoid overburdening limited computing resources or costly re-certi cation of ight software due to instrumentation. No currently available SHM capabilities (or combinations of currently existing SHM capabilities) come anywhere close to satisfying these three criteria yet NASA will require such intelligent, hardwareenabled sensor and software safety and health management for introducing autonomous UAS into the National Airspace System (NAS). We propose a novel approach of creating modular building blocks for combining responsive runtime monitoring of temporal logic system safety requirements with model-based diagnosis and Bayesian network-based probabilistic analysis. Our proposed research program includes both developing this novel approach and demonstrating its capabilities using the NASA Swift UAS as a demonstration platform.

Evaluation of Fatigue Crack Growth and Fracture Properties of Cryogenic Model Materials

NASA Technical Reports Server (NTRS)

Newman, John A.; Forth, Scott C.; Everett, Richard A., Jr.; Newman, James C., Jr.; Kimmel, William M.

2002-01-01

The criteria used to prevent failure of wind-tunnel models and support hardware were revised as part of a project to enhance the capabilities of cryogenic wind tunnel testing at NASA Langley Research Center. Specifically, damage-tolerance fatigue life prediction methods are now required for critical components, and material selection criteria are more general and based on laboratory test data. The suitability of two candidate model alloys (AerMet 100 and C-250 steel) was investigated by obtaining the fatigue crack growth and fracture data required for a damage-tolerance fatigue life analysis. Finally, an example is presented to illustrate the newly implemented damage tolerance analyses required of wind-tunnel model system components.

Independent Orbiter Assessment (IOA): Assessment of the orbital maneuvering system FMEA/CIL, volume 1

NASA Technical Reports Server (NTRS)

Prust, Chet D.; Haufler, W. A.; Marino, A. J.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Orbital Maneuvering System (OMS) hardware and Electrical Power Distribution and Control (EPD and C), generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline. This report documents the results of that comparison for the Orbiter OMS hardware. The IOA analysis defined the OMS as being comprised of the following subsystems: helium pressurization, propellant storage and distribution, Orbital Maneuvering Engine, and EPD and C. The IOA product for the OMS analysis consisted of 284 hardware and 667 EPD and C failure mode worksheets that resulted in 160 hardware and 216 EPD and C potential critical items (PCIs) being identified. A comparison was made of the IOA product to the NASA FMEA/CIL baseline which consisted of 101 hardware and 142 EPD and C CIL items.

Allergic reaction to vanadium causes a diffuse eczematous eruption and titanium alloy orthopedic implant failure.

PubMed

Engelhart, Sally; Segal, Robert J

2017-04-01

Allergy as a cause of adverse outcomes in patients with implanted orthopedic hardware is controversial. Allergy to titanium-based implants has not been well researched, as titanium is traditionally thought to be inert. We highlight the case of a patient who developed systemic dermatitis and implant failure after surgical placement of a titanium alloy (Ti6Al4V) plate in the left foot. The hardware was removed and the eruption cleared in the following weeks. The plate and screws were submitted for metal analysis. The elemental composition of both the plate and screws included 3 major elements-titanium, aluminum, and vanadium-as well as trace elements. Metal analysis revealed that the plate and screws had different microstructures, and electrochemical studies demonstrated that galvanic corrosion could have occurred between the plate and screws due to their different microstructures, contributing to the release of vanadium in vivo. The patient was patch tested with several metals including components of the implant and had a positive patch test reaction only to vanadium trichloride. These findings support a diagnosis of vanadium allergy and suggests that clinicians should consider including vanadium when patch testing patients with a suspected allergic reaction to vanadium-containing implants.

Towards Real-time, On-board, Hardware-Supported Sensor and Software Health Management for Unmanned Aerial Systems

NASA Technical Reports Server (NTRS)

Schumann, Johann; Rozier, Kristin Y.; Reinbacher, Thomas; Mengshoel, Ole J.; Mbaya, Timmy; Ippolito, Corey

2013-01-01

Unmanned aerial systems (UASs) can only be deployed if they can effectively complete their missions and respond to failures and uncertain environmental conditions while maintaining safety with respect to other aircraft as well as humans and property on the ground. In this paper, we design a real-time, on-board system health management (SHM) capability to continuously monitor sensors, software, and hardware components for detection and diagnosis of failures and violations of safety or performance rules during the flight of a UAS. Our approach to SHM is three-pronged, providing: (1) real-time monitoring of sensor and/or software signals; (2) signal analysis, preprocessing, and advanced on the- fly temporal and Bayesian probabilistic fault diagnosis; (3) an unobtrusive, lightweight, read-only, low-power realization using Field Programmable Gate Arrays (FPGAs) that avoids overburdening limited computing resources or costly re-certification of flight software due to instrumentation. Our implementation provides a novel approach of combining modular building blocks, integrating responsive runtime monitoring of temporal logic system safety requirements with model-based diagnosis and Bayesian network-based probabilistic analysis. We demonstrate this approach using actual data from the NASA Swift UAS, an experimental all-electric aircraft.

Commercial Aircraft Integrated Vehicle Health Management Study

NASA Technical Reports Server (NTRS)

Reveley, Mary S.; Briggs, Jeffrey L.; Evans, Joni K.; Jones, Sharon Monica; Kurtoglu, Tolga; Leone, Karen M.; Sandifer, Carl E.; Thomas, Megan A.

2010-01-01

Statistical data and literature from academia, industry, and other government agencies were reviewed and analyzed to establish requirements for fixture work in detection, diagnosis, prognosis, and mitigation for IVHM related hardware and software. Around 15 to 20 percent of commercial aircraft accidents between 1988 and 2003 involved inalftfnctions or failures of some aircraft system or component. Engine and landing gear failures/malfunctions dominate both accidents and incidents. The IVI vl Project research technologies were found to map to the Joint Planning and Development Office's National Research and Development Plan (RDP) as well as the Safety Working Group's National Aviation Safety Strategic. Plan (NASSP). Future directions in Aviation Technology as related to IVHlvl were identified by reviewing papers from three conferences across a five year time span. A total of twenty-one trend groups in propulsion, aeronautics and aircraft categories were compiled. Current and ftiture directions of IVHM related technologies were gathered and classified according to eight categories: measurement and inspection, sensors, sensor management, detection, component and subsystem monitoring, diagnosis, prognosis, and mitigation.

The EMIR experience in the use of software control simulators to speed up the time to telescope

NASA Astrophysics Data System (ADS)

Lopez Ramos, Pablo; López-Ruiz, J. C.; Moreno Arce, Heidy; Rosich, Josefina; Perez Menor, José Maria

2012-09-01

One of the main problems facing development teams working on instrument control systems consists on the need to access mechanisms which are not available until well into the integration phase. The need to work with real hardware creates additional problems like, among others: certain faults cannot be tested due to the possibility of hardware damage, taking the system to the limit may shorten its operational lifespan and the full system may not be available during some periods due to maintenance and/or testing of individual components. These problems can be treated with the use of simulators and by applying software/hardware standards. Since information on the construction and performance of electro-mechanical systems is available at relatively early stages of the project, simulators are developed in advance (before the existence of the mechanism) or, if conventions and standards have been correctly followed, a previously developed simulator might be used. This article describes our experience in building software simulators and the main advantages we have identified, which are: the control software can be developed even in the absence of real hardware, critical tests can be prepared using the simulated systems, test system behavior for hardware failure situations that represent a risk of the real system, and the speed up of in house integration of the entire instrument. The use of simulators allows us to reduce development, testing and integration time.

A Plug and Play GNC Architecture Using FPGA Components

NASA Technical Reports Server (NTRS)

KrishnaKumar, K.; Kaneshige, J.; Waterman, R.; Pires, C.; Ippoloito, C.

2005-01-01

The goal of Plug and Play, or PnP, is to allow hardware and software components to work together automatically, without requiring manual setup procedures. As a result, new or replacement hardware can be plugged into a system and automatically configured with the appropriate resource assignments. However, in many cases it may not be practical or even feasible to physically replace hardware components. One method for handling these types of situations is through the incorporation of reconfigurable hardware such as Field Programmable Gate Arrays, or FPGAs. This paper describes a phased approach to developing a Guidance, Navigation, and Control (GNC) architecture that expands on the traditional concepts of PnP, in order to accommodate hardware reconfiguration without requiring detailed knowledge of the hardware. This is achieved by establishing a functional based interface that defines how the hardware will operate, and allow the hardware to reconfigure itself. The resulting system combines the flexibility of manipulating software components with the speed and efficiency of hardware.

A Framework for the Development of Scalable Heterogeneous Robot Teams with Dynamically Distributed Processing

NASA Astrophysics Data System (ADS)

Martin, Adrian

As the applications of mobile robotics evolve it has become increasingly less practical for researchers to design custom hardware and control systems for each problem. This research presents a new approach to control system design that looks beyond end-of-lifecycle performance and considers control system structure, flexibility, and extensibility. Toward these ends the Control ad libitum philosophy is proposed, stating that to make significant progress in the real-world application of mobile robot teams the control system must be structured such that teams can be formed in real-time from diverse components. The Control ad libitum philosophy was applied to the design of the HAA (Host, Avatar, Agent) architecture: a modular hierarchical framework built with provably correct distributed algorithms. A control system for exploration and mapping, search and deploy, and foraging was developed to evaluate the architecture in three sets of hardware-in-the-loop experiments. First, the basic functionality of the HAA architecture was studied, specifically the ability to: a) dynamically form the control system, b) dynamically form the robot team, c) dynamically form the processing network, and d) handle heterogeneous teams. Secondly, the real-time performance of the distributed algorithms was tested, and proved effective for the moderate sized systems tested. Furthermore, the distributed Just-in-time Cooperative Simultaneous Localization and Mapping (JC-SLAM) algorithm demonstrated accuracy equal to or better than traditional approaches in resource starved scenarios, while reducing exploration time significantly. The JC-SLAM strategies are also suitable for integration into many existing particle filter SLAM approaches, complementing their unique optimizations. Thirdly, the control system was subjected to concurrent software and hardware failures in a series of increasingly complex experiments. Even with unrealistically high rates of failure the control system was able to successfully complete its tasks. The HAA implementation designed following the Control ad libitum philosophy proved to be capable of dynamic team formation and extremely robust against both hardware and software failure; and, due to the modularity of the system there is significant potential for reuse of assets and future extensibility. One future goal is to make the source code publically available and establish a forum for the development and exchange of new agents.

Design Criteria for Controlling Stress Corrosion Cracking

NASA Technical Reports Server (NTRS)

Franklin, D. B.

1987-01-01

This document sets forth the criteria to be used in the selection of materials for space vehicles and associated equipment and facilities so that failure resulting from stress corrosion will be prevented. The requirements established herein apply to all metallic components proposed for use in space vehicles and other flight hardware, ground support equipment, and facilities for testing. These requirements are applicable not only to items designed and fabricated by MSFC (Marshall Space Flight Center) and its prime contractors, but also to items supplied to the prime contractor by subcontractors and vendors.

Pulse Code Modulation (PCM) encoder handbook for Aydin Vector MMP-600 series system

NASA Technical Reports Server (NTRS)

Currier, S. F.; Powell, W. R.

1986-01-01

The hardware and software characteristics of a time division multiplex system are described. The system is used to sample analog and digital data. The data is merged with synchronization information to produce a serial pulse coded modulation (PCM) bit stream. Information presented herein is required by users to design compatible interfaces and assure effective utilization of this encoder system. GSFC/Wallops Flight Facility has flown approximately 50 of these systems through 1984 on sounding rockets with no inflight failures. Aydin Vector manufactures all of the components for these systems.

System Risk Balancing Profiles: Software Component

NASA Technical Reports Server (NTRS)

Kelly, John C.; Sigal, Burton C.; Gindorf, Tom

2000-01-01

The Software QA / V&V guide will be reviewed and updated based on feedback from NASA organizations and others with a vested interest in this area. Hardware, EEE Parts, Reliability, and Systems Safety are a sample of the future guides that will be developed. Cost Estimates, Lessons Learned, Probability of Failure and PACTS (Prevention, Avoidance, Control or Test) are needed to provide a more complete risk management strategy. This approach to risk management is designed to help balance the resources and program content for risk reduction for NASA's changing environment.

Hardware and software reliability estimation using simulations

NASA Technical Reports Server (NTRS)

Swern, Frederic L.

1994-01-01

The simulation technique is used to explore the validation of both hardware and software. It was concluded that simulation is a viable means for validating both hardware and software and associating a reliability number with each. This is useful in determining the overall probability of system failure of an embedded processor unit, and improving both the code and the hardware where necessary to meet reliability requirements. The methodologies were proved using some simple programs, and simple hardware models.

Systems special investigation group overview

NASA Technical Reports Server (NTRS)

Mason, James B.; Dursch, Harry; Edelman, Joel

1992-01-01

The Systems Special Investigation Group (SIG) has undertaken investigations in the four major engineering disciplines represented by LDEF hardware: electrical, mechanical, thermal, and optical systems. Testing was planned for the highest possible level of assembly, and top level system tests for nearly all systems were performed at this time. Testing to date was performed on a mix of LDEF and individual experimenter systems. No electrical or mechanical system level failures attributed to the spaceflight environment were detected by the Systems SIG. Some low cost electrical components were used successfully, although relays were a continuing problem. Extensive mechanical galling was observed, but no evidence of coldwelding was identified. A working index of observed systems anomalies was created and will be used to support the tracking and resolution of these effects. LDEF hardware currently available to the Systems SIG includes most of the LDEF facility systems hardware, and some significant experimenter hardware as well. A series of work packages was developed for each of several subsystem types where further testing is of critical interest. The Systems SIG is distributing a regular newsletter to the greater LDEF community in order to maintain coherence in an investigation which is widely scattered both in subject matter and in geography. Circulation of this informal document has quadrupled in its first year.

Systems special investigation group overview

NASA Technical Reports Server (NTRS)

Mason, James B.; Dursch, Harry; Edelman, Joel

1991-01-01

The Systems Special Investigation Group (SIG) has undertaken investigations in the four major engineering disciplines represented in the Long Duration Exposure Facility (LDEF) hardware: electrical, mechanical, thermal, and optical systems. Testing was planned for the highest possible level of assembly, and top level system tests for nearly all systems were performed at this time. To date, testing was performed on a mix of LDEF and individual experimenter systems. No electrical or mechanical system level failures attributed to the spaceflight environment have yet been detected. Some low cost electrical components were used successfully, although relays were a continuing problem. Mechanical galling was observed unexpectedly, but no evidence of cold welding was identified yet. A working index of observed systems anomalies was created and will be used to support the tracking and resolution of these effects. The LDEF hardware currently available to the Systems SIG includes most of the LDEF systems hardware, and some significant experimenter hardware as well. A series of work packages was developed for each of several subsystem types where further testing is of critical interest. The System SIG is distributing a regular newsletter to the greater LDEF community in order to maintain coherence in an investigation which is widely scattered both in subject matter and in geography. Circulation of this informal document has quadrupled in its first year.

Failure Analysis of Nonvolatile Residue (NVR) Analyzer Model SP-1000

NASA Technical Reports Server (NTRS)

Potter, Joseph C.

2011-01-01

National Aeronautics and Space Administration (NASA) subcontractor Wiltech contacted the NASA Electrical Lab (NE-L) and requested a failure analysis of a Solvent Purity Meter; model SP-IOOO produced by the VerTis Instrument Company. The meter, used to measure the contaminate in a solvent to determine the relative contamination on spacecraft flight hardware and ground servicing equipment, had been inoperable and in storage for an unknown amount of time. NE-L was asked to troubleshoot the unit and make a determination on what may be required to make the unit operational. Through the use of general troubleshooting processes and the review of a unit in service at the time of analysis, the unit was found to be repairable but would need the replacement of multiple components.

Terrestrial Sources of X-Ray Radiation and Their Effects on NASA Flight Hardware

NASA Technical Reports Server (NTRS)

Kniffin, Scott

2016-01-01

X-rays are an energetic and penetrating form of ionizing electromagnetic radiation, which can degrade NASA flight hardware. The main concern posed by such radiation is degradation of active electronic devices and, in some cases, diodes. Non-electronic components are only damaged at doses that far exceed the point where any electronic device would be destroyed. For the purposes of this document, flight hardware can be taken to mean an entire instrument, the flight electronics within the instrument or the individual microelectronic devices in the flight electronics. This document will discuss and describe the ways in which NASA flight hardware might be exposed to x-rays, what is and isn't a concern, and how to tell the difference. First, we must understand what components in flight hardware may be vulnerable to degradation or failure as a result of being exposed to ionizing radiation, such as x-rays. As stated above, bulk materials (structural metals, plastics, etc.) are generally only affected by ionizing radiation at very high dose levels. Likewise, passive electronic components (e.g. resistors, capacitors, most diodes) are strongly resistant to exposure to x-rays, except at very high doses. The main concerns arise when active components, that is, components like discrete transistors and microelectronic devices, are exposed to ionizing radiation. Active components are designed to respond to minute changes in currents and voltages in the circuit. As such, it is not surprising that exposure to ionizing radiation, which creates ionized and therefore electrically active particles, may degrade the way the hardware performs. For the most part, the mechanism for this degradation is trapping of the charges generated by ionizing radiation by defects in dielectric materials in the hardware. As such, the degree of damage is a function of both the quantity of ionizing radiation exposure and the physical characteristics of the hardware itself. The metric that describes the level of exposure to ionizing radiation is total ionizing dose (TID). The unit of TID is the rad, which is defined as 100 ergs absorbed per gram of material. Dose can be expressed in other units, for example grays (gy), where 1 gy = 100 rads. The actual fluence of radiation needed to deliver a rad depends on the absorbing material, so units of dose are usually stated in reference to the material of interest. That is, for microelectronic devices, the unit of dose is generally rad (Si) or rad (SiO2). However, the definition of absorbed dose in this fashion has the advantage that the type of radiation causing the ionization can be normalized so that a realistic and adequate comparison can be made. The sensitivity of microelectronic parts to TID varies over many orders of magnitude. (Note: Doses to humans are typically expressed in rems-or roentgen-equivalent-man-which measures tissue damage, and depends on the type of radiation, as well as the dose in rads.) Thus far, the "softest" parts tested at NASA showed damage at 500 rads (Si), while parts that are radiation-hardened by design can remain functional to doses on the order of 107 rads (Si). This broad range of sensitivity highlights one of the most important considerations when considering the effects of radiation on electronic parts: In order to determine whether a radiation exposure is a concern for a particular part, one must understand the technologies used in the part and their vulnerabilities to TID damage. A NASA radiation expert should be consulted to obtain such information.

Independent Orbiter Assessment (IOA): Analysis of the ascent thrust vector control actuator subsystem

NASA Technical Reports Server (NTRS)

Wilson, R. E.; Riccio, J. R.

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Ascent Thrust Vector Control (ATVC) Actuator hardware are documented. The function of the Ascent Thrust Vector Control Actuators (ATVC) is to gimbal the main engines to provide for attitude and flight path control during ascent. During first stage flight, the SRB nozzles provide nearly all the steering. After SRB separation, the Orbiter is steered by gimbaling of its main engines. There are six electrohydraulic servoactuators, one pitch and one yaw for each of the three main engines. Each servoactuator is composed of four electrohydraulic servovalve assemblies, one second stage power spool valve assembly, one primary piston assembly and a switching valve. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Critical failures resulting in loss of ATVC were mainly due to loss of hydraulic fluid, fluid contamination and mechanical failures.

49 CFR 238.105 - Train electronic hardware and software safety.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and software system safety as part of the pre-revenue service testing of the equipment. (d)(1... safely by initiating a full service brake application in the event of a hardware or software failure that... 49 Transportation 4 2010-10-01 2010-10-01 false Train electronic hardware and software safety. 238...

77 FR 22611 - Certain Set-Top Boxes, and Hardware and Software Components Thereof; Determination Not To Review...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-16

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-761] Certain Set-Top Boxes, and Hardware and Software Components Thereof; Determination Not To Review Initial Determination Terminating... certain set-top boxes, and hardware and software components thereof by reason of infringement of various...

Supportability Technologies for Future Exploration Missions

NASA Technical Reports Server (NTRS)

Watson, Kevin; Thompson, Karen

2007-01-01

Future long-duration human exploration missions will be challenged by resupply limitations and mass and volume constraints. Consequently, it will be essential that the logistics footprint required to support these missions be minimized and that capabilities be provided to make them highly autonomous from a logistics perspective. Strategies to achieve these objectives include broad implementation of commonality and standardization at all hardware levels and across all systems, repair of failed hardware at the lowest possible hardware level, and manufacture of structural and mechanical replacement components as needed. Repair at the lowest hardware levels will require the availability of compact, portable systems for diagnosis of failures in electronic systems and verification of system functionality following repair. Rework systems will be required that enable the removal and replacement of microelectronic components with minimal human intervention to minimize skill requirements and training demand for crews. Materials used in the assembly of electronic systems (e.g. solders, fluxes, conformal coatings) must be compatible with the available repair methods and the spacecraft environment. Manufacturing of replacement parts for structural and mechanical applications will require additive manufacturing systems that can generate near-net-shape parts from the range of engineering alloys employed in the spacecraft structure and in the parts utilized in other surface systems. These additive manufacturing processes will need to be supported by real-time non-destructive evaluation during layer-additive processing for on-the-fly quality control. This will provide capabilities for quality control and may serve as an input for closed-loop process control. Additionally, non-destructive methods should be available for material property determination. These nondestructive evaluation processes should be incorporated with the additive manufacturing process - providing an in-process capability to ensure that material deposited during layer-additive processing meets required material property criteria.

Biomorphic Multi-Agent Architecture for Persistent Computing

NASA Technical Reports Server (NTRS)

Lodding, Kenneth N.; Brewster, Paul

2009-01-01

A multi-agent software/hardware architecture, inspired by the multicellular nature of living organisms, has been proposed as the basis of design of a robust, reliable, persistent computing system. Just as a multicellular organism can adapt to changing environmental conditions and can survive despite the failure of individual cells, a multi-agent computing system, as envisioned, could adapt to changing hardware, software, and environmental conditions. In particular, the computing system could continue to function (perhaps at a reduced but still reasonable level of performance) if one or more component( s) of the system were to fail. One of the defining characteristics of a multicellular organism is unity of purpose. In biology, the purpose is survival of the organism. The purpose of the proposed multi-agent architecture is to provide a persistent computing environment in harsh conditions in which repair is difficult or impossible. A multi-agent, organism-like computing system would be a single entity built from agents or cells. Each agent or cell would be a discrete hardware processing unit that would include a data processor with local memory, an internal clock, and a suite of communication equipment capable of both local line-of-sight communications and global broadcast communications. Some cells, denoted specialist cells, could contain such additional hardware as sensors and emitters. Each cell would be independent in the sense that there would be no global clock, no global (shared) memory, no pre-assigned cell identifiers, no pre-defined network topology, and no centralized brain or control structure. Like each cell in a living organism, each agent or cell of the computing system would contain a full description of the system encoded as genes, but in this case, the genes would be components of a software genome.

ACARA - AVAILABILITY, COST AND RESOURCE ALLOCATION

NASA Technical Reports Server (NTRS)

Viterna, L. A.

1994-01-01

ACARA is a program for analyzing availability, lifecycle cost, and resource scheduling. It uses a statistical Monte Carlo method to simulate a system's capacity states as well as component failure and repair. Component failures are modelled using a combination of exponential and Weibull probability distributions. ACARA schedules component replacement to achieve optimum system performance. The scheduling will comply with any constraints on component production, resupply vehicle capacity, on-site spares, or crew manpower and equipment. ACARA is capable of many types of analyses and trade studies because of its integrated approach. It characterizes the system performance in terms of both state availability and equivalent availability (a weighted average of state availability). It can determine the probability of exceeding a capacity state to assess reliability and loss of load probability. It can also evaluate the effect of resource constraints on system availability and lifecycle cost. ACARA interprets the results of a simulation and displays tables and charts for: (1) performance, i.e., availability and reliability of capacity states, (2) frequency of failure and repair, (3) lifecycle cost, including hardware, transportation, and maintenance, and (4) usage of available resources, including mass, volume, and maintenance man-hours. ACARA incorporates a user-friendly, menu-driven interface with full screen data entry. It provides a file management system to store and retrieve input and output datasets for system simulation scenarios. ACARA is written in APL2 using the APL2 interpreter for IBM PC compatible systems running MS-DOS. Hardware requirements for the APL2 system include 640K of RAM, 2Mb of extended memory, and an 80386 or 80486 processor with an 80x87 math co-processor. A dot matrix printer is required if the user wishes to print a graph from a results table. A sample MS-DOS executable is provided on the distribution medium. The executable contains licensed material from the APL2 for the IBM PC product which is program property of IBM; Copyright IBM Corporation 1988 - All rights reserved. It is distributed with IBM's permission. The standard distribution medium for this program is a set of three 5.25 inch 360K MS-DOS format diskettes. The contents of the diskettes are compressed using the PKWARE archiving tools. The utility to unarchive the files, PKUNZIP.EXE, is included. ACARA was developed in 1992.

Intelligent Design and Intelligent Failure

NASA Technical Reports Server (NTRS)

Jerman, Gregory

2015-01-01

Good Evening, my name is Greg Jerman and for nearly a quarter century I have been performing failure analysis on NASA's aerospace hardware. During that time I had the distinct privilege of keeping the Space Shuttle flying for two thirds of its history. I have analyzed a wide variety of failed hardware from simple electrical cables to cryogenic fuel tanks to high temperature turbine blades. During this time I have found that for all the time we spend intelligently designing things, we need to be equally intelligent about understanding why things fail. The NASA Flight Director for Apollo 13, Gene Kranz, is best known for the expression "Failure is not an option." However, NASA history is filled with failures both large and small, so it might be more accurate to say failure is inevitable. It is how we react and learn from our failures that makes the difference.

Evaluation of wheelchair seating system crashworthiness: "drop hook"-type seat attachment hardware.

PubMed

Bertocci, G; Ha, D; Deemer, E; Karg, P

2001-04-01

To evaluate the crashworthiness of commercially available hardware that attaches seat surfaces to the wheelchair frame. A low cost static crashworthiness test procedure that simulates a frontal impact motor vehicle crash. Safety testing laboratory. Eleven unique sets of drop-hook hardware made of carbon steel (4), stainless steel (4), and aluminum (3). Replicated seat-loading conditions associated with a 20g/48 kph frontal impact. Test criterion for seat loading was 16,680 N (3750 lb). Failure load and deflection of seat surface. None of the hardware sets tested met the crashworthiness test criterion. All failed at less than 50% of the load that seating hardware could be exposed to in a 20g/48 kph frontal impact. The primary failure mode was excessive deformation, leading to an unstable seat support surface. Results suggest that commercially available seating drop hooks may be unable to withstand loading associated with a frontal crash and may not be the best option for use with transport wheelchairs.

Reliability and Qualification of Hardware to Enhance the Mission Assurance of JPL/NASA Projects

NASA Technical Reports Server (NTRS)

Ramesham, Rajeshuni

2010-01-01

Packaging Qualification and Verification (PQV) and life testing of advanced electronic packaging, mechanical assemblies (motors/actuators), and interconnect technologies (flip-chip), platinum temperature thermometer attachment processes, and various other types of hardware for Mars Exploration Rover (MER)/Mars Science Laboratory (MSL), and JUNO flight projects was performed to enhance the mission assurance. The qualification of hardware under extreme cold to hot temperatures was performed with reference to various project requirements. The flight like packages, assemblies, test coupons, and subassemblies were selected for the study to survive three times the total number of expected temperature cycles resulting from all environmental and operational exposures occurring over the life of the flight hardware including all relevant manufacturing, ground operations, and mission phases. Qualification/life testing was performed by subjecting flight-like qualification hardware to the environmental temperature extremes and assessing any structural failures, mechanical failures or degradation in electrical performance due to either overstress or thermal cycle fatigue. Experimental flight qualification test results will be described in this presentation.

KSC-2012-4344

NASA Image and Video Library

2012-08-09

CAPE CANAVERAL, Fla. – During a free-flight test of the Project Morpheus vehicle at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida, the vehicle lifted off the ground and then experienced a hardware component failure, which prevented it from maintaining stable flight. Engineers are looking into the test data and the agency will release information as it becomes available. Failures such as these were anticipated prior to the test, and are part of the development process for any complex spaceflight hardware. Testing of the prototype lander had been ongoing at NASA’s Johnson Space Center in Houston in preparation for its first free-flight test at Kennedy Space Center. Morpheus was manufactured and assembled at JSC and Armadillo Aerospace. Morpheus is large enough to carry 1,100 pounds of cargo to the moon – for example, a humanoid robot, a small rover, or a small laboratory to convert moon dust into oxygen. The primary focus of the test is to demonstrate an integrated propulsion and guidance, navigation and control system that can fly a lunar descent profile to exercise the Autonomous Landing and Hazard Avoidance Technology, or ALHAT, safe landing sensors and closed-loop flight control. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA

Framework for a space shuttle main engine health monitoring system

NASA Technical Reports Server (NTRS)

Hawman, Michael W.; Galinaitis, William S.; Tulpule, Sharayu; Mattedi, Anita K.; Kamenetz, Jeffrey

1990-01-01

A framework developed for a health management system (HMS) which is directed at improving the safety of operation of the Space Shuttle Main Engine (SSME) is summarized. An emphasis was placed on near term technology through requirements to use existing SSME instrumentation and to demonstrate the HMS during SSME ground tests within five years. The HMS framework was developed through an analysis of SSME failure modes, fault detection algorithms, sensor technologies, and hardware architectures. A key feature of the HMS framework design is that a clear path from the ground test system to a flight HMS was maintained. Fault detection techniques based on time series, nonlinear regression, and clustering algorithms were developed and demonstrated on data from SSME ground test failures. The fault detection algorithms exhibited 100 percent detection of faults, had an extremely low false alarm rate, and were robust to sensor loss. These algorithms were incorporated into a hierarchical decision making strategy for overall assessment of SSME health. A preliminary design for a hardware architecture capable of supporting real time operation of the HMS functions was developed. Utilizing modular, commercial off-the-shelf components produced a reliable low cost design with the flexibility to incorporate advances in algorithm and sensor technology as they become available.

The upgrade of the H.E.S.S. cameras

NASA Astrophysics Data System (ADS)

Giavitto, Gianluca; Ashton, Terry; Balzer, Arnim; Berge, David; Brun, Francois; Chaminade, Thomas; Delagnes, Eric; Fontaine, Gerard; Füßling, Matthias; Giebels, Berrie; Glicenstein, Jean-Francois; Gräber, Tobias; Hinton, Jim; Jahnke, Albert; Klepser, Stefan; Kossatz, Marko; Kretzschmann, Axel; Lefranc, Valentin; Leich, Holger; Lüdecke, Hartmut; Lypova, Iryna; Manigot, Pascal; Marandon, Vincent; Moulin, Emmanuel; de Naurois, Mathieu; Nayman, Patrick; Ohm, Stefan; Penno, Marek; Ross, Duncan; Salek, David; Schade, Markus; Schwab, Thomas; Simoni, Rachel; Stegmann, Christian; Steppa, Constantin; Thornhill, Julian; Toussnel, Francois

2017-01-01

The High Energy Stereoscopic System (H.E.S.S.) is an array of five imaging atmospheric Cherenkov telescopes (IACT) located in Namibia. In order to assure the continuous operation of H.E.S.S. at its full sensitivity until and possibly beyond the advent of CTA, the older cameras, installed in 2003, are currently undergoing an extensive upgrade. Its goals are reducing the system failure rate, reducing the dead time and improving the overall performance of the array. All camera components have been upgraded, except the mechanical structure and the photo-multiplier tubes (PMTs). Novel technical solutions have been introduced: the upgraded readout electronics is based on the NECTAr analog memory chip; the control of the hardware is carried out by an FPGA coupled to an embedded ARM computer; the control software was re-written from scratch and it is based on modern C++ open source libraries. These hardware and software solutions offer very good performance, robustness and flexibility. The first camera was fielded in July 2015 and has been successfully commissioned; the rest is scheduled to be upgraded in September 2016. The present contribution describes the design, the testing and the performance of the new H.E.S.S. camera and its components.

[MaRS Project

NASA Technical Reports Server (NTRS)

Aruljothi, Arunvenkatesh

2016-01-01

The Space Exploration Division of the Safety and Mission Assurances Directorate is responsible for reducing the risk to Human Space Flight Programs by providing system safety, reliability, and risk analysis. The Risk & Reliability Analysis branch plays a part in this by utilizing Probabilistic Risk Assessment (PRA) and Reliability and Maintainability (R&M) tools to identify possible types of failure and effective solutions. A continuous effort of this branch is MaRS, or Mass and Reliability System, a tool that was the focus of this internship. Future long duration space missions will have to find a balance between the mass and reliability of their spare parts. They will be unable take spares of everything and will have to determine what is most likely to require maintenance and spares. Currently there is no database that combines mass and reliability data of low level space-grade components. MaRS aims to be the first database to do this. The data in MaRS will be based on the hardware flown on the International Space Stations (ISS). The components on the ISS have a long history and are well documented, making them the perfect source. Currently, MaRS is a functioning excel workbook database; the backend is complete and only requires optimization. MaRS has been populated with all the assemblies and their components that are used on the ISS; the failures of these components are updated regularly. This project was a continuation on the efforts of previous intern groups. Once complete, R&M engineers working on future space flight missions will be able to quickly access failure and mass data on assemblies and components, allowing them to make important decisions and tradeoffs.

Lox/Gox related failures during Space Shuttle Main Engine development

NASA Technical Reports Server (NTRS)

Cataldo, C. E.

1981-01-01

Specific rocket engine hardware and test facility system failures are described which were caused by high pressure liquid and/or gaseous oxygen reactions. The failures were encountered during the development and testing of the space shuttle main engine. Failure mechanisms are discussed as well as corrective actions taken to prevent or reduce the potential of future failures.

Parameterized hardware description as object oriented hardware model implementation

NASA Astrophysics Data System (ADS)

Drabik, Pawel K.

2010-09-01

The paper introduces novel model for design, visualization and management of complex, highly adaptive hardware systems. The model settles component oriented environment for both hardware modules and software application. It is developed on parameterized hardware description research. Establishment of stable link between hardware and software, as a purpose of designed and realized work, is presented. Novel programming framework model for the environment, named Graphic-Functional-Components is presented. The purpose of the paper is to present object oriented hardware modeling with mentioned features. Possible model implementation in FPGA chips and its management by object oriented software in Java is described.

Engine throat/nozzle optics for plume spectroscopy

NASA Technical Reports Server (NTRS)

Bickford, R. L.; Duncan, D. B.

1991-01-01

The Task 2.0 Engine Throat/Nozzle Optics for Plume Spectroscopy, effort was performed under the NASA LeRC Development of Life Prediction Capabilities for Liquid Propellant Rocket Engines program. This Task produced the engineering design of an optical probe to enable spectroscopic measurements within the SSME main chamber. The probe mounts on the SSME nozzle aft manifold and collects light emitted from the throat plane and chamber. Light collected by the probe is transferred to a spectrometer through a fiber optic cable. The design analyses indicate that the probe will function throughout the engine operating cycle and is suitable for both test stand and flight operations. By detecting metallic emissions that are indicative of component degradation or incipient failure, engine shutdown can be initiated before catastrophic failure. This capability will protect valuable test stand hardware and provide enhanced mission safety.

Independent Orbiter Assessment (IOA): Assessment of the reaction control system, volume 1

NASA Technical Reports Server (NTRS)

Prust, Chet D.; Hartman, Dan W.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the aft and forward Reaction Control System (RCS) hardware, and Electrical Power Distribution and Control (EPD and C), generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline. This report documents the results of that comparison for the Orbiter RCS hardware and EPD and C systems. The IOA product for the RCS analysis consisted of 208 hardware and 2064 EPD and C failure mode worksheets that resulted in 141 hardware and 449 EPD and C potential critical items (PCIs) being identified. A comparison was made of the IOA product to the NASA FMEA/CIL baseline. After comparison and discussions with the NASA subsystem manager, 96 hardware issues, 83 of which concern CIL items or PCIs, and 280 EPD and C issues, 158 of which concern CIL items or PCIs, and 280 EPD and C issues, 158 of which concern CIL items or PCIs, remain unresolved. Volume 1 contains the subsystem description, assessment results, and some of the IOA worksheets.

Safety considerations in the design and operation of large wind turbines

NASA Technical Reports Server (NTRS)

Reilly, D. H.

1979-01-01

The engineering and safety techniques used to assure the reliable and safe operation of large wind turbine generators utilizing the Mod 2 Wind Turbine System Program as an example is described. The techniques involve a careful definition of the wind turbine's natural and operating environments, use of proven structural design criteria and analysis techniques, an evaluation of potential failure modes and hazards, and use of a fail safe and redundant component engineering philosophy. The role of an effective quality assurance program, tailored to specific hardware criticality, and the checkout and validation program developed to assure system integrity are described.

Integrated Hardware and Software for No-Loss Computing

NASA Technical Reports Server (NTRS)

James, Mark

2007-01-01

When an algorithm is distributed across multiple threads executing on many distinct processors, a loss of one of those threads or processors can potentially result in the total loss of all the incremental results up to that point. When implementation is massively hardware distributed, then the probability of a hardware failure during the course of a long execution is potentially high. Traditionally, this problem has been addressed by establishing checkpoints where the current state of some or part of the execution is saved. Then in the event of a failure, this state information can be used to recompute that point in the execution and resume the computation from that point. A serious problem arises when one distributes a problem across multiple threads and physical processors is that one increases the likelihood of the algorithm failing due to no fault of the scientist but as a result of hardware faults coupled with operating system problems. With good reason, scientists expect their computing tools to serve them and not the other way around. What is novel here is a unique combination of hardware and software that reformulates an application into monolithic structure that can be monitored in real-time and dynamically reconfigured in the event of a failure. This unique reformulation of hardware and software will provide advanced aeronautical technologies to meet the challenges of next-generation systems in aviation, for civilian and scientific purposes, in our atmosphere and in atmospheres of other worlds. In particular, with respect to NASA s manned flight to Mars, this technology addresses the critical requirements for improving safety and increasing reliability of manned spacecraft.

Morpheus 1.5A Lander Failure Investigation Results

NASA Technical Reports Server (NTRS)

Munday, Steve; Olansen, John

2013-01-01

On August 9th, 2012, the Morpheus 1.5 Vertical Testbed (VTB) crashed during Free Flight 2 (FF2) at KSC SLF, resulting in the loss of 1.5 VTB hardware. JSC/KSC Morpheus team immediately executed the pre-rehearsed Emergency Action Plan to protect personnel and property, so damage was limited to 1.5 VTB hardware. JSC/KSC Morpheus team secured data and mapped & recovered debris. Project had pre-declared loss of VTB to be a test failure, not a mishap.

Orbiter subsystem hardware/software interaction analysis. Volume 8: AFT reaction control system, part 2

NASA Technical Reports Server (NTRS)

Becker, D. D.

1980-01-01

The orbiter subsystems and interfacing program elements which interact with the orbiter computer flight software are analyzed. The failure modes identified in the subsystem/element failure mode and effects analysis are examined. Potential interaction with the software is examined through an evaluation of the software requirements. The analysis is restricted to flight software requirements and excludes utility/checkout software. The results of the hardware/software interaction analysis for the forward reaction control system are presented.

Test Results of the RS-44 Integrated Component Evaluator Liquid Oxygen/Hydrogen Rocket Engine

NASA Technical Reports Server (NTRS)

Sutton, R. F.; Lariviere, B. W.

1993-01-01

An advanced LOX/LH2 expander cycle rocket engine, producing 15,000 lbf thrust for Orbital Transfer Vehicle missions, was tested to determine ignition, transition, and main stage characteristics. Detail design and fabrication of the pump fed RS44 integrated component evaluator (ICE) was accomplished using company discretionary resources and was tested under this contracted effort. Successful demonstrations were completed to about the 50 percent fuel turbopump power level (87,000 RPM), but during this last test, a high pressure fuel turbopump (HPFTP) bearing failed curtailing the test program. No other hardware were affected by the HPFTP premature shutdown. The ICE operations matched well with the predicted start transient simulations. The tests demonstrated the feasibility of a high performance advanced expander cycle engine. All engine components operated nominally, except for the HPFTP, during the engine hot-fire tests. A failure investigation was completed using company discretionary resources.

International Space Station (ISS) Low Pressure Intramodule Quick Disconnect Failures

NASA Technical Reports Server (NTRS)

Lewis, John F.; Harris, Danny; Link, Dwight; Morrison, Russel

2004-01-01

A failure of an ISS intermodule Quick Disconnect (QD) during protoflight vibration testing of ISS regenerative Environmental Control and Life Support (ECLS) hardware led to the discovery of QD design, manufacturing, and test flaws which can yield the male QD susceptible to failure of the secondary housing seal and inadequate housing assembly locking mechanisms. Discovery of this failure had large implications when considering that currently there are 399 similar units on orbit and approximately 1100 units on the ground integrated into flight hardware. Discovery of the nature of the failure required testing and analysis and implementation of a recovery plan requiring part screening and review of element level and project hazard analysis to determine if secondary seals are required. Implementation also involves coordination with the Nodes and MPLM project offices, Regenerative ECLS Project, ISS Payloads, JAXA, ESA, and ISS Logistics and Maintenance.

Commercial Aircraft Maintenance Experience Relating to Engine External Hardware

NASA Technical Reports Server (NTRS)

Soditus, Sharon M.

2006-01-01

Airlines are extremely sensitive to the amount of dollars spent on maintaining the external engine hardware in the field. Analysis reveals that many problems revolve around a central issue, reliability. Fuel and oil leakage due to seal failure and electrical fault messages due to wire harness failures play a major role in aircraft delays and cancellations (D&C's) and scheduled maintenance. Correcting these items on the line requires a large investment of engineering resources and manpower after the fact. The smartest and most cost effective philosophy is to build the best hardware the first time. The only way to do that is to completely understand and model the operating environment, study the field experience of similar designs and to perform extensive testing.

Guest Editor's Introduction: Special section on dependable distributed systems

NASA Astrophysics Data System (ADS)

Fetzer, Christof

1999-09-01

We rely more and more on computers. For example, the Internet reshapes the way we do business. A `computer outage' can cost a company a substantial amount of money. Not only with respect to the business lost during an outage, but also with respect to the negative publicity the company receives. This is especially true for Internet companies. After recent computer outages of Internet companies, we have seen a drastic fall of the shares of the affected companies. There are multiple causes for computer outages. Although computer hardware becomes more reliable, hardware related outages remain an important issue. For example, some of the recent computer outages of companies were caused by failed memory and system boards, and even by crashed disks - a failure type which can easily be masked using disk mirroring. Transient hardware failures might also look like software failures and, hence, might be incorrectly classified as such. However, many outages are software related. Faulty system software, middleware, and application software can crash a system. Dependable computing systems are systems we can rely on. Dependable systems are, by definition, reliable, available, safe and secure [3]. This special section focuses on issues related to dependable distributed systems. Distributed systems have the potential to be more dependable than a single computer because the probability that all computers in a distributed system fail is smaller than the probability that a single computer fails. However, if a distributed system is not built well, it is potentially less dependable than a single computer since the probability that at least one computer in a distributed system fails is higher than the probability that one computer fails. For example, if the crash of any computer in a distributed system can bring the complete system to a halt, the system is less dependable than a single-computer system. Building dependable distributed systems is an extremely difficult task. There is no silver bullet solution. Instead one has to apply a variety of engineering techniques [2]: fault-avoidance (minimize the occurrence of faults, e.g. by using a proper design process), fault-removal (remove faults before they occur, e.g. by testing), fault-evasion (predict faults by monitoring and reconfigure the system before failures occur), and fault-tolerance (mask and/or contain failures). Building a system from scratch is an expensive and time consuming effort. To reduce the cost of building dependable distributed systems, one would choose to use commercial off-the-shelf (COTS) components whenever possible. The usage of COTS components has several potential advantages beyond minimizing costs. For example, through the widespread usage of a COTS component, design failures might be detected and fixed before the component is used in a dependable system. Custom-designed components have to mature without the widespread in-field testing of COTS components. COTS components have various potential disadvantages when used in dependable systems. For example, minimizing the time to market might lead to the release of components with inherent design faults (e.g. use of `shortcuts' that only work most of the time). In addition, the components might be more complex than needed and, hence, potentially have more design faults than simpler components. However, given economic constraints and the ability to cope with some of the problems using fault-evasion and fault-tolerance, only for a small percentage of systems can one justify not using COTS components. Distributed systems built from current COTS components are asynchronous systems in the sense that there exists no a priori known bound on the transmission delay of messages or the execution time of processes. When designing a distributed algorithm, one would like to make sure (e.g. by testing or verification) that it is correct, i.e. satisfies its specification. Many distributed algorithms make use of consensus (eventually all non-crashed processes have to agree on a value), leader election (a crashed leader is eventually replaced by a new leader, but at any time there is at most one leader) or a group membership detection service (a crashed process is eventually suspected to have crashed but only crashed processes are suspected). From a theoretical point of view, the service specifications given for such services are not implementable in asynchronous systems. In particular, for each implementation one can derive a counter example in which the service violates its specification. From a practical point of view, the consensus, the leader election, and the membership detection problem are solvable in asynchronous distributed systems. In this special section, Raynal and Tronel show how to bridge this difference by showing how to implement the group membership detection problem with a negligible probability [1] to fail in an asynchronous system. The group membership detection problem is specified by a liveness condition (L) and a safety property (S): (L) if a process p crashes, then eventually every non-crashed process q has to suspect that p has crashed; and (S) if a process q suspects p, then p has indeed crashed. One can show that either (L) or (S) is implementable, but one cannot implement both (L) and (S) at the same time in an asynchronous system. In practice, one only needs to implement (L) and (S) such that the probability that (L) or (S) is violated becomes negligible. Raynal and Tronel propose and analyse a protocol that implements (L) with certainty and that can be tuned such that the probability that (S) is violated becomes negligible. Designing and implementing distributed fault-tolerant protocols for asynchronous systems is a difficult but not an impossible task. A fault-tolerant protocol has to detect and mask certain failure classes, e.g. crash failures and message omission failures. There is a trade-off between the performance of a fault-tolerant protocol and the failure classes the protocol can tolerate. One wants to tolerate as many failure classes as needed to satisfy the stochastic requirements of the protocol [1] while still maintaining a sufficient performance. Since clients of a protocol have different requirements with respect to the performance/fault-tolerance trade-off, one would like to be able to customize protocols such that one can select an appropriate performance/fault-tolerance trade-off. In this special section Hiltunen et al describe how one can compose protocols from micro-protocols in their Cactus system. They show how a group RPC system can be tailored to the needs of a client. In particular, they show how considering additional failure classes affects the performance of a group RPC system. References [1] Cristian F 1991 Understanding fault-tolerant distributed systems Communications of ACM 34 (2) 56-78 [2] Heimerdinger W L and Weinstock C B 1992 A conceptual framework for system fault tolerance Technical Report 92-TR-33, CMU/SEI [3] Laprie J C (ed) 1992 Dependability: Basic Concepts and Terminology (Vienna: Springer)

System for detecting operating errors in a variable valve timing engine using pressure sensors

DOEpatents

Wiles, Matthew A.; Marriot, Craig D

2013-07-02

A method and control module includes a pressure sensor data comparison module that compares measured pressure volume signal segments to ideal pressure volume segments. A valve actuation hardware remedy module performs a hardware remedy in response to comparing the measured pressure volume signal segments to the ideal pressure volume segments when a valve actuation hardware failure is detected.

Field Programmable Gate Array Failure Rate Estimation Guidelines for Launch Vehicle Fault Tree Models

NASA Technical Reports Server (NTRS)

Al Hassan, Mohammad; Novack, Steven D.; Hatfield, Glen S.; Britton, Paul

2017-01-01

Today's launch vehicles complex electronic and avionic systems heavily utilize the Field Programmable Gate Array (FPGA) integrated circuit (IC). FPGAs are prevalent ICs in communication protocols such as MIL-STD-1553B, and in control signal commands such as in solenoid/servo valves actuations. This paper will demonstrate guidelines to estimate FPGA failure rates for a launch vehicle, the guidelines will account for hardware, firmware, and radiation induced failures. The hardware contribution of the approach accounts for physical failures of the IC, FPGA memory and clock. The firmware portion will provide guidelines on the high level FPGA programming language and ways to account for software/code reliability growth. The radiation portion will provide guidelines on environment susceptibility as well as guidelines on tailoring other launch vehicle programs historical data to a specific launch vehicle.

Implementation of a High-Speed FPGA and DSP Based FFT Processor for Improving Strain Demodulation Performance in a Fiber-Optic-Based Sensing System

NASA Technical Reports Server (NTRS)

Farley, Douglas L.

2005-01-01

NASA's Aviation Safety and Security Program is pursuing research in on-board Structural Health Management (SHM) technologies for purposes of reducing or eliminating aircraft accidents due to system and component failures. Under this program, NASA Langley Research Center (LaRC) is developing a strain-based structural health-monitoring concept that incorporates a fiber optic-based measuring system for acquiring strain values. This fiber optic-based measuring system provides for the distribution of thousands of strain sensors embedded in a network of fiber optic cables. The resolution of strain value at each discrete sensor point requires a computationally demanding data reduction software process that, when hosted on a conventional processor, is not suitable for near real-time measurement. This report describes the development and integration of an alternative computing environment using dedicated computing hardware for performing the data reduction. Performance comparison between the existing and the hardware-based system is presented.

Addressing failures in exascale computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snir, Marc; Wisniewski, Robert W.; Abraham, Jacob A.

2014-05-01

We present here a report produced by a workshop on “Addressing Failures in Exascale Computing” held in Park City, Utah, August 4–11, 2012. The charter of this workshop was to establish a common taxonomy about resilience across all the levels in a computing system; discuss existing knowledge on resilience across the various hardware and software layers of an exascale system; and build on those results, examining potential solutions from both a hardware and software perspective and focusing on a combined approach. The workshop brought together participants with expertise in applications, system software, and hardware; they came from industry, government, andmore » academia; and their interests ranged from theory to implementation. The combination allowed broad and comprehensive discussions and led to this document, which summarizes and builds on those discussions.« less

Addressing Failures in Exascale Computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snir, Marc; Wisniewski, Robert; Abraham, Jacob

2014-01-01

We present here a report produced by a workshop on Addressing failures in exascale computing' held in Park City, Utah, 4-11 August 2012. The charter of this workshop was to establish a common taxonomy about resilience across all the levels in a computing system, discuss existing knowledge on resilience across the various hardware and software layers of an exascale system, and build on those results, examining potential solutions from both a hardware and software perspective and focusing on a combined approach. The workshop brought together participants with expertise in applications, system software, and hardware; they came from industry, government, andmore » academia, and their interests ranged from theory to implementation. The combination allowed broad and comprehensive discussions and led to this document, which summarizes and builds on those discussions.« less

Fifty Years of Observing Hardware and Human Behavior

NASA Technical Reports Server (NTRS)

McMann, Joe

2011-01-01

During this half-day workshop, Joe McMann presented the lessons learned during his 50 years of experience in both industry and government, which included all U.S. manned space programs, from Mercury to the ISS. He shared his thoughts about hardware and people and what he has learned from first-hand experience. Included were such topics as design, testing, design changes, development, failures, crew expectations, hardware, requirements, and meetings.

Data Applicability of Heritage and New Hardware for Launch Vehicle System Reliability Models

NASA Technical Reports Server (NTRS)

Al Hassan Mohammad; Novack, Steven

2015-01-01

Many launch vehicle systems are designed and developed using heritage and new hardware. In most cases, the heritage hardware undergoes modifications to fit new functional system requirements, impacting the failure rates and, ultimately, the reliability data. New hardware, which lacks historical data, is often compared to like systems when estimating failure rates. Some qualification of applicability for the data source to the current system should be made. Accurately characterizing the reliability data applicability and quality under these circumstances is crucial to developing model estimations that support confident decisions on design changes and trade studies. This presentation will demonstrate a data-source classification method that ranks reliability data according to applicability and quality criteria to a new launch vehicle. This method accounts for similarities/dissimilarities in source and applicability, as well as operating environments like vibrations, acoustic regime, and shock. This classification approach will be followed by uncertainty-importance routines to assess the need for additional data to reduce uncertainty.

Recycling Flight Hardware Components and Systems to Reduce Next Generation Research Costs

NASA Technical Reports Server (NTRS)

Turner, Wlat

2011-01-01

With the recent 'new direction' put forth by President Obama identifying NASA's new focus in research rather than continuing on a path to return to the Moon and Mars, the focus of work at Kennedy Space Center (KSC) may be changing dramatically. Research opportunities within the micro-gravity community potentially stands at the threshold of resurgence when the new direction of the agency takes hold for the next generation of experimenters. This presentation defines a strategy for recycling flight experiment components or part numbers, in order to reduce research project costs, not just in component selection and fabrication, but in expediting qualification of hardware for flight. A key component of the strategy is effective communication of relevant flight hardware information and available flight hardware components to researchers, with the goal of 'short circuiting' the design process for flight experiments

KSC-2012-4345

NASA Image and Video Library

2012-08-09

CAPE CANAVERAL, Fla. – During a free-flight test of the Project Morpheus vehicle at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida, the vehicle lifted off the ground and then experienced a hardware component failure, which prevented it from maintaining stable flight. No one was injured and the resulting fire was extinguished by Kennedy fire personnel. Engineers are looking into the test data and the agency will release information as it becomes available. Failures such as these were anticipated prior to the test, and are part of the development process for any complex spaceflight hardware. Testing of the prototype lander had been ongoing at NASA’s Johnson Space Center in Houston in preparation for its first free-flight test at Kennedy Space Center. Morpheus was manufactured and assembled at JSC and Armadillo Aerospace. Morpheus is large enough to carry 1,100 pounds of cargo to the moon – for example, a humanoid robot, a small rover, or a small laboratory to convert moon dust into oxygen. The primary focus of the test is to demonstrate an integrated propulsion and guidance, navigation and control system that can fly a lunar descent profile to exercise the Autonomous Landing and Hazard Avoidance Technology, or ALHAT, safe landing sensors and closed-loop flight control. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA

KSC-2012-4346

NASA Image and Video Library

2012-08-09

CAPE CANAVERAL, Fla. – During a free-flight test of the Project Morpheus vehicle at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida, the vehicle lifted off the ground and then experienced a hardware component failure, which prevented it from maintaining stable flight. No one was injured and the resulting fire was extinguished by Kennedy fire personnel. Engineers are looking into the test data and the agency will release information as it becomes available. Failures such as these were anticipated prior to the test, and are part of the development process for any complex spaceflight hardware. Testing of the prototype lander had been ongoing at NASA’s Johnson Space Center in Houston in preparation for its first free-flight test at Kennedy Space Center. Morpheus was manufactured and assembled at JSC and Armadillo Aerospace. Morpheus is large enough to carry 1,100 pounds of cargo to the moon – for example, a humanoid robot, a small rover, or a small laboratory to convert moon dust into oxygen. The primary focus of the test is to demonstrate an integrated propulsion and guidance, navigation and control system that can fly a lunar descent profile to exercise the Autonomous Landing and Hazard Avoidance Technology, or ALHAT, safe landing sensors and closed-loop flight control. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA

Real time on-chip sequential adaptive principal component analysis for data feature extraction and image compression

NASA Technical Reports Server (NTRS)

Duong, T. A.

2004-01-01

In this paper, we present a new, simple, and optimized hardware architecture sequential learning technique for adaptive Principle Component Analysis (PCA) which will help optimize the hardware implementation in VLSI and to overcome the difficulties of the traditional gradient descent in learning convergence and hardware implementation.

Independent Orbiter Assessment (IOA): Assessment of the EPD and C/remote manipulator system FMEA/CIL

NASA Technical Reports Server (NTRS)

Robinson, W. W.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Electrical Power Distribution and Control (EPD and C)/Remote Manipulator System (RMS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA analysis of the EPD and C/RMS hardware initially generated 345 failure mode worksheets and identified 117 Potential Critical Items (PCIs) before starting the assessment process. These analysis results were compared to the proposed NASA Post 51-L baseline of 132 FMEAs and 66 CIL items.

Failure of the Trailing Umbilical System Disconnect Actuator on the International Space Station

NASA Technical Reports Server (NTRS)

Gilmore, Adam; Schmitt, Chris; Merritt, Laura; Bolton, V. J.

2008-01-01

In December of 2005, one of two trailing umbilical cables used on the International Space Station (ISS) Mobile Transporter (MT) was inadvertently severed by an internal cutter system designed to free a snagged cable or jammed reel while transporting hazardous payloads. The mechanism s intended means of actuation is electrical; however, troubleshooting revealed a mechanical actuation occurred. The investigation of the failed component revealed several lessons learned in developing hardware requirements, understanding and following the rationale behind the requirements throughout the design life cycle, understanding the impacts of gaps and tolerances in a mechanism, and the importance of identifying critical steps during assembly.

Failure of the Trailing Umbilical System Disconnect Actuator on the International Space Station

NASA Technical Reports Server (NTRS)

Gilmore, Adam; Schmitt, Chris; Merritt, Laura; Bolton, V. J.

2008-01-01

In December of 2005, one of two trailing umbilical cables used on the International Space Station (ISS) Mobile Transporter (MT) was inadvertently severed by an internal cutter system designed to free a snagged cable or jammed reel while transporting hazardous payloads. The mechanism s intended means of actuation is electrical; however, troubleshooting revealed a mechanical actuation occurred. The investigation of the failed component revealed several lessons learned in developing hardware requirements, understanding and following the rationale behind the requirements throughout the design life cycle, understanding the impacts of gaps and tolerances in a mechanism, and the importance of identifying critical steps during assembly

Restoring Redundancy to the MAP Propulsion System

NASA Technical Reports Server (NTRS)

O'Donnell, James R., Jr.; Davis, Gary T.; Ward, David K.; Bauer, Frank H. (Technical Monitor)

2002-01-01

The Microwave Anisotropy Probe (MAP) is a follow-on to the Differential Microwave Radiometer (DMR) instrument on the Cosmic Background Explorer (COBE). Due to the MAP project's limited mass, power, and financial resources, a traditional reliability concept including fully redundant components was not feasible. The MAP design employs selective hardware redundancy, along with backup software modes and algorithms, to improve the odds of mission success. In particular, MAP's propulsion system, which is used for orbit maneuvers and momentum management, uses eight thrusters positioned and oriented in such a way that its thruster-based attitude control modes can maintain three-axis attitude control in the event of the failure of any one thruster.

Systems Suitable for Information Professionals.

ERIC Educational Resources Information Center

Blair, John C., Jr.

1983-01-01

Describes computer operating systems applicable to microcomputers, noting hardware components, advantages and disadvantages of each system, local area networks, distributed processing, and a fully configured system. Lists of hardware components (disk drives, solid state disk emulators, input/output and memory components, and processors) and…

Monitoring and Hardware Management for Critical Fusion Plasma Instrumentation

NASA Astrophysics Data System (ADS)

Carvalho, Paulo F.; Santos, Bruno; Correia, Miguel; Combo, Álvaro M.; Rodrigues, AntÓnio P.; Pereira, Rita C.; Fernandes, Ana; Cruz, Nuno; Sousa, Jorge; Carvalho, Bernardo B.; Batista, AntÓnio J. N.; Correia, Carlos M. B. A.; Gonçalves, Bruno

2018-01-01

Controlled nuclear fusion aims to obtain energy by particles collision confined inside a nuclear reactor (Tokamak). These ionized particles, heavier isotopes of hydrogen, are the main elements inside of plasma that is kept at high temperatures (millions of Celsius degrees). Due to high temperatures and magnetic confinement, plasma is exposed to several sources of instabilities which require a set of procedures by the control and data acquisition systems throughout fusion experiments processes. Control and data acquisition systems often used in nuclear fusion experiments are based on the Advanced Telecommunication Computer Architecture (AdvancedTCA®) standard introduced by the Peripheral Component Interconnect Industrial Manufacturers Group (PICMG®), to meet the demands of telecommunications that require large amount of data (TB) transportation at high transfer rates (Gb/s), to ensure high availability including features such as reliability, serviceability and redundancy. For efficient plasma control, systems are required to collect large amounts of data, process it, store for later analysis, make critical decisions in real time and provide status reports either from the experience itself or the electronic instrumentation involved. Moreover, systems should also ensure the correct handling of detected anomalies and identified faults, notify the system operator of occurred events, decisions taken to acknowledge and implemented changes. Therefore, for everything to work in compliance with specifications it is required that the instrumentation includes hardware management and monitoring mechanisms for both hardware and software. These mechanisms should check the system status by reading sensors, manage events, update inventory databases with hardware system components in use and maintenance, store collected information, update firmware and installed software modules, configure and handle alarms to detect possible system failures and prevent emergency scenarios occurrences. The goal is to ensure high availability of the system and provide safety operation, experiment security and data validation for the fusion experiment. This work aims to contribute to the joint effort of the IPFN control and data acquisition group to develop a hardware management and monitoring application for control and data acquisition instrumentation especially designed for large scale tokamaks like ITER.

Standardization Efforts for Mechanical Testing and Design of Advanced Ceramic Materials and Components

NASA Technical Reports Server (NTRS)

Salem, Jonathan A.; Jenkins, Michael G.

2003-01-01

Advanced aerospace systems occasionally require the use of very brittle materials such as sapphire and ultra-high temperature ceramics. Although great progress has been made in the development of methods and standards for machining, testing and design of component from these materials, additional development and dissemination of standard practices is needed. ASTM Committee C28 on Advanced Ceramics and ISO TC 206 have taken a lead role in the standardization of testing for ceramics, and recent efforts and needs in standards development by Committee C28 on Advanced Ceramics will be summarized. In some cases, the engineers, etc. involved are unaware of the latest developments, and traditional approaches applicable to other material systems are applied. Two examples of flight hardware failures that might have been prevented via education and standardization will be presented.

Independent Orbiter Assessment (IOA): Analysis of the life support and airlock support subsystems

NASA Technical Reports Server (NTRS)

Arbet, Jim; Duffy, R.; Barickman, K.; Saiidi, Mo J.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Life Support System (LSS) and Airlock Support System (ALSS). Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. The LSS provides for the management of the supply water, collection of metabolic waste, management of waste water, smoke detection, and fire suppression. The ALSS provides water, oxygen, and electricity to support an extravehicular activity in the airlock.

Independent Orbiter Assessment (IOA): Analysis of the auxiliary power unit

NASA Technical Reports Server (NTRS)

Barnes, J. E.

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Auxiliary Power Unit (APU). The APUs are required to provide power to the Orbiter hydraulics systems during ascent and entry flight phases for aerosurface actuation, main engine gimballing, landing gear extension, and other vital functions. For analysis purposes, the APU system was broken down into ten functional subsystems. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. A preponderance of 1/1 criticality items were related to failures that allowed the hydrazine fuel to escape into the Orbiter aft compartment, creating a severe fire hazard, and failures that caused loss of the gas generator injector cooling system.

Analysis of particulates on tape lift samples

NASA Astrophysics Data System (ADS)

Moision, Robert M.; Chaney, John A.; Panetta, Chris J.; Liu, De-Ling

2014-09-01

Particle counts on tape lift samples taken from a hardware surface exceeded threshold requirements in six successive tests despite repeated cleaning of the surface. Subsequent analysis of the particle size distributions of the failed tests revealed that the handling and processing of the tape lift samples may have played a role in the test failures. In order to explore plausible causes for the observed size distribution anomalies, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed to perform chemical analysis on collected particulates. SEM/EDX identified Na and S containing particles on the hardware samples in a size range identified as being responsible for the test failures. ToF-SIMS was employed to further examine the Na and S containing particulates and identified the molecular signature of sodium alkylbenzene sulfonates, a common surfactant used in industrial detergent. The root cause investigation suggests that the tape lift test failures originated from detergent residue left behind on the glass slides used to mount and transport the tape following sampling and not from the hardware surface.

NASA Applications and Lessons Learned in Reliability Engineering

NASA Technical Reports Server (NTRS)

Safie, Fayssal M.; Fuller, Raymond P.

2011-01-01

Since the Shuttle Challenger accident in 1986, communities across NASA have been developing and extensively using quantitative reliability and risk assessment methods in their decision making process. This paper discusses several reliability engineering applications that NASA has used over the year to support the design, development, and operation of critical space flight hardware. Specifically, the paper discusses several reliability engineering applications used by NASA in areas such as risk management, inspection policies, components upgrades, reliability growth, integrated failure analysis, and physics based probabilistic engineering analysis. In each of these areas, the paper provides a brief discussion of a case study to demonstrate the value added and the criticality of reliability engineering in supporting NASA project and program decisions to fly safely. Examples of these case studies discussed are reliability based life limit extension of Shuttle Space Main Engine (SSME) hardware, Reliability based inspection policies for Auxiliary Power Unit (APU) turbine disc, probabilistic structural engineering analysis for reliability prediction of the SSME alternate turbo-pump development, impact of ET foam reliability on the Space Shuttle System risk, and reliability based Space Shuttle upgrade for safety. Special attention is given in this paper to the physics based probabilistic engineering analysis applications and their critical role in evaluating the reliability of NASA development hardware including their potential use in a research and technology development environment.

Developing an Integration Infrastructure for Distributed Engine Control Technologies

NASA Technical Reports Server (NTRS)

Culley, Dennis; Zinnecker, Alicia; Aretskin-Hariton, Eliot; Kratz, Jonathan

2014-01-01

Turbine engine control technology is poised to make the first revolutionary leap forward since the advent of full authority digital engine control in the mid-1980s. This change aims squarely at overcoming the physical constraints that have historically limited control system hardware on aero-engines to a federated architecture. Distributed control architecture allows complex analog interfaces existing between system elements and the control unit to be replaced by standardized digital interfaces. Embedded processing, enabled by high temperature electronics, provides for digitization of signals at the source and network communications resulting in a modular system at the hardware level. While this scheme simplifies the physical integration of the system, its complexity appears in other ways. In fact, integration now becomes a shared responsibility among suppliers and system integrators. While these are the most obvious changes, there are additional concerns about performance, reliability, and failure modes due to distributed architecture that warrant detailed study. This paper describes the development of a new facility intended to address the many challenges of the underlying technologies of distributed control. The facility is capable of performing both simulation and hardware studies ranging from component to system level complexity. Its modular and hierarchical structure allows the user to focus their interaction on specific areas of interest.

Evolutionary online behaviour learning and adaptation in real robots.

PubMed

Silva, Fernando; Correia, Luís; Christensen, Anders Lyhne

2017-07-01

Online evolution of behavioural control on real robots is an open-ended approach to autonomous learning and adaptation: robots have the potential to automatically learn new tasks and to adapt to changes in environmental conditions, or to failures in sensors and/or actuators. However, studies have so far almost exclusively been carried out in simulation because evolution in real hardware has required several days or weeks to produce capable robots. In this article, we successfully evolve neural network-based controllers in real robotic hardware to solve two single-robot tasks and one collective robotics task. Controllers are evolved either from random solutions or from solutions pre-evolved in simulation. In all cases, capable solutions are found in a timely manner (1 h or less). Results show that more accurate simulations may lead to higher-performing controllers, and that completing the optimization process in real robots is meaningful, even if solutions found in simulation differ from solutions in reality. We furthermore demonstrate for the first time the adaptive capabilities of online evolution in real robotic hardware, including robots able to overcome faults injected in the motors of multiple units simultaneously, and to modify their behaviour in response to changes in the task requirements. We conclude by assessing the contribution of each algorithmic component on the performance of the underlying evolutionary algorithm.

Top-down and bottom-up definitions of human failure events in human reliability analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boring, Ronald Laurids

2014-10-01

In the probabilistic risk assessments (PRAs) used in the nuclear industry, human failure events (HFEs) are determined as a subset of hardware failures, namely those hardware failures that could be triggered by human action or inaction. This approach is top-down, starting with hardware faults and deducing human contributions to those faults. Elsewhere, more traditionally human factors driven approaches would tend to look at opportunities for human errors first in a task analysis and then identify which of those errors is risk significant. The intersection of top-down and bottom-up approaches to defining HFEs has not been carefully studied. Ideally, both approachesmore » should arrive at the same set of HFEs. This question is crucial, however, as human reliability analysis (HRA) methods are generalized to new domains like oil and gas. The HFEs used in nuclear PRAs tend to be top-down—defined as a subset of the PRA—whereas the HFEs used in petroleum quantitative risk assessments (QRAs) often tend to be bottom-up—derived from a task analysis conducted by human factors experts. The marriage of these approaches is necessary in order to ensure that HRA methods developed for top-down HFEs are also sufficient for bottom-up applications.« less

Independent Orbiter Assessment (IOA): Analysis of the extravehicular mobility unit

NASA Technical Reports Server (NTRS)

Raffaelli, Gary G.

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Extravehicular Mobility Unit (EMU) hardware. The EMU is an independent anthropomorphic system that provides environmental protection, mobility, life support, and communications for the Shuttle crewmember to perform Extravehicular Activity (EVA) in Earth orbit. Two EMUs are included on each baseline Orbiter mission, and consumables are provided for three two-man EVAs. The EMU consists of the Life Support System (LSS), Caution and Warning System (CWS), and the Space Suit Assembly (SSA). Each level of hardware was evaluated and analyzed for possible failure modes and effects. The majority of these PCIs are resultant from failures which cause loss of one or more primary functions: pressurization, oxygen delivery, environmental maintenance, and thermal maintenance. It should also be noted that the quantity of PCIs would significantly increase if the SOP were to be treated as an emergency system rather than as an unlike redundant element.

Automatic calibration and signal switching system for the particle beam fusion research data acquisition facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyer, W.B.

1979-09-01

This report describes both the hardware and software components of an automatic calibration and signal system (Autocal) for the data acquisition system for the Sandia particle beam fusion research accelerators Hydra, Proto I, and Proto II. The Autocal hardware consists of off-the-shelf commercial equipment. The various hardware components, special modifications and overall system configuration are described. Special software has been developed to support the Autocal hardware. Software operation and maintenance are described.

D0 General Support: The Use of Programmable Logic Controllers (PLCS) at D0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hance, R.; /Fermilab

With the exception of control of heating, ventilation, and air conditioning (HVAC) ventilation fans, and their shutdown in the case of smoke in the ducts, all implementations of Programmable Logic Controllers (PLCs) in Dzero have been made within the fundamental premise that no uncertified PLC apparatus shall be entrusted with the safety of equipment or personnel. Thus although PLCs are used to control and monitor all manner of intricate equipment, simple hardware interlocks and relief devices provide basic protection against component failure, control failure, or inappropriate control operation. Nevertheless, this report includes two observations as follows: (1) It may bemore » prudent to reconfigure the link between the Pyrotronics system and the HVAC system such that the Pyrotronics system provides interlocks to the ventilation fans instead of control inputs to the uncertified HVAC PLCs. Although the Pyrotronics system is certified and maintained to life safety standards, the HVAC system is not. A hardware or software failure of the HVAC system probably should not be allowed to result in the situation where the ventilation fans in a smoke filled duct continue to operate. Dan Markley is investigating this matter. (2) It may also be prudent to examine the network security of those systems connected to the Fermilab WAN (HVAC, Cryo, and Solenoid Controls). Even though the impact of a successful hack might only be to operations, it might nevertheless be disruptive and could be expensive. The risks should perhaps be analyzed. One of the most attractive features of these systems, from a user's viewpoint, is their unlimited networking. The unlimited networking that makes the systems so convenient to legitimate access also makes them vulnerable to illegitimate access.« less

Free-Swinging Failure Tolerance for Robotic Manipulators

NASA Technical Reports Server (NTRS)

English, James

1997-01-01

Under this GSRP fellowship, software-based failure-tolerance techniques were developed for robotic manipulators. The focus was on failures characterized by the loss of actuator torque at a joint, called free-swinging failures. The research results spanned many aspects of the free-swinging failure-tolerance problem, from preparing for an expected failure to discovery of postfailure capabilities to establishing efficient methods to realize those capabilities. Developed algorithms were verified using computer-based dynamic simulations, and these were further verified using hardware experiments at Johnson Space Center.

Independent Orbiter Assessment (IOA): Assessment of the main propulsion subsystem FMEA/CIL, volume 2

NASA Technical Reports Server (NTRS)

Holden, K. A.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Main Propulsion System (MPS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were than compared to available data from the Rockwell Downey/NASA JSC FMEA/CIL review. Volume 2 continues the presentation of IOA worksheets for MPS hardware items.

Independent Orbiter Assessment (IOA): Assessment of the communication and tracking subsystem, volume 2

NASA Technical Reports Server (NTRS)

Long, W. C.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed and analysis of the Communication and Tracking hardware, generating draft failure modes and potential critical items. The IOA results were then compared to the NASA FMEA/CIL baseline. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter Communication and Tracking hardware. Volume 2 continues the presentation of IOA worksheets.

Independent Orbiter Assessment (IOA): Assessment of the reaction control system, volume 3

NASA Technical Reports Server (NTRS)

Prust, Chet D.; Hartman, Dan W.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the aft and forward Reaction Control System (RCS) hardware and Electrical Power Distribution and Control (EPD and C), generating draft failure modes and potential critical items. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline. This report documents the results of that comparison for the Orbiter RCS hardware and EPD and C systems. Volume 3 continues the presentation of IOA worksheets.

Independent Orbiter Assessment (IOA): Assessment of the reaction control system, volume 2

NASA Technical Reports Server (NTRS)

Prust, Chet D.; Hartman, Dan W.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the aft and forward Reaction Control System (RCS) hardware and Electrical Power Distribution and Control (EPD and C), generating draft failure modes and potential critical items. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline. This report documents the results of that comparison for the Orbiter RCS hardware and EPD and C systems. Volume 2 continues the presentation of IOA worksheets.

Managing a Multisite Academic-Private Radiology Practice Reading Environment: Impact of IT Downtimes on Enterprise Efficiency.

PubMed

Becker, Murray; Goldszal, Alberto; Detal, Julie; Gronlund-Jacob, Judith; Epstein, Robert

2015-06-01

The aim of this study was to assess whether the complex radiology IT infrastructures needed for large, geographically diversified, radiology practices are inherently stable with respect to system downtimes, and to characterize the nature of the downtimes to better understand their impact on radiology department workflow. All radiology IT unplanned downtimes over a 12-month period in a hybrid academic-private practice that performs all interpretations in-house (no commercial "nighthawk" services) for approximately 900,000 studies per year, originating at 6 hospitals, 10 outpatient imaging centers, and multiple low-volume off-hours sites, were logged and characterized using 5 downtime metrics: duration, etiology, failure type, extent, and severity. In 12 consecutive months, 117 unplanned downtimes occurred with the following characteristics: duration: median time = 3.5 hours with 34% <1.5 hours and 30% >12 hours; etiology: 87% were due to software malfunctions, and 13% to hardware malfunctions; failure type: 88% were transient component failures, 12% were complete component failures; extent: all sites experienced downtimes, but downtimes were always localized to a subset of sites, and no system-wide downtimes occurred; severity (impact on radiologist workflow): 47% had minimal impact, 50% moderate impact, and 3% severe impact. In the complex radiology IT system that was studied, downtimes were common; they were usually a result of transient software malfunctions; the geographic extent was always localized rather than system wide; and most often, the impacts on radiologist workflow were modest. Copyright © 2015 American College of Radiology. Published by Elsevier Inc. All rights reserved.

The Integrated Hazard Analysis Integrator

NASA Technical Reports Server (NTRS)

Morris, A. Terry; Massie, Michael J.

2009-01-01

Hazard analysis addresses hazards that arise in the design, development, manufacturing, construction, facilities, transportation, operations and disposal activities associated with hardware, software, maintenance, operations and environments. An integrated hazard is an event or condition that is caused by or controlled by multiple systems, elements, or subsystems. Integrated hazard analysis (IHA) is especially daunting and ambitious for large, complex systems such as NASA s Constellation program which incorporates program, systems and element components that impact others (International Space Station, public, International Partners, etc.). An appropriate IHA should identify all hazards, causes, controls and verifications used to mitigate the risk of catastrophic loss of crew, vehicle and/or mission. Unfortunately, in the current age of increased technology dependence, there is the tendency to sometimes overlook the necessary and sufficient qualifications of the integrator, that is, the person/team that identifies the parts, analyzes the architectural structure, aligns the analysis with the program plan and then communicates/coordinates with large and small components, each contributing necessary hardware, software and/or information to prevent catastrophic loss. As viewed from both Challenger and Columbia accidents, lack of appropriate communication, management errors and lack of resources dedicated to safety were cited as major contributors to these fatalities. From the accident reports, it would appear that the organizational impact of managers, integrators and safety personnel contributes more significantly to mission success and mission failure than purely technological components. If this is so, then organizations who sincerely desire mission success must put as much effort in selecting managers and integrators as they do when designing the hardware, writing the software code and analyzing competitive proposals. This paper will discuss the necessary and sufficient requirements of one of the significant contributors to mission success, the IHA integrator. Discussions will be provided to describe both the mindset required as well as deleterious assumptions/behaviors to avoid when integrating within a large scale system.

Independent Orbiter Assessment (IOA): Assessment of the Orbiter Experiment (OEX) subsystem

NASA Technical Reports Server (NTRS)

Compton, J. M.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Orbiter Experiments (OEX) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. The results of that comparison for the Orbiter OEX hardware are documented. The IOA product for the OEX analysis consisted of 82 failure mode worksheets that resulted in two potential critical items being identified.

49 CFR Appendix C to Part 236 - Safety Assurance Criteria and Processes

Code of Federal Regulations, 2010 CFR

2010-10-01

... system (all its elements including hardware and software) must be designed to assure safe operation with... unsafe errors in the software due to human error in the software specification, design, or coding phases... (hardware or software, or both) are used in combination to ensure safety. If a common mode failure exists...

Development and Application of a Portable Health Algorithms Test System

NASA Technical Reports Server (NTRS)

Melcher, Kevin J.; Fulton, Christopher E.; Maul, William A.; Sowers, T. Shane

2007-01-01

This paper describes the development and initial demonstration of a Portable Health Algorithms Test (PHALT) System that is being developed by researchers at the NASA Glenn Research Center (GRC). The PHALT System was conceived as a means of evolving the maturity and credibility of algorithms developed to assess the health of aerospace systems. Comprising an integrated hardware-software environment, the PHALT System allows systems health management algorithms to be developed in a graphical programming environment; to be tested and refined using system simulation or test data playback; and finally, to be evaluated in a real-time hardware-in-the-loop mode with a live test article. In this paper, PHALT System development is described through the presentation of a functional architecture, followed by the selection and integration of hardware and software. Also described is an initial real-time hardware-in-the-loop demonstration that used sensor data qualification algorithms to diagnose and isolate simulated sensor failures in a prototype Power Distribution Unit test-bed. Success of the initial demonstration is highlighted by the correct detection of all sensor failures and the absence of any real-time constraint violations.

Reliability and Maintainability Analysis for the Amine Swingbed Carbon Dioxide Removal System

NASA Technical Reports Server (NTRS)

Dunbar, Tyler

2016-01-01

I have performed a reliability & maintainability analysis for the Amine Swingbed payload system. The Amine Swingbed is a carbon dioxide removal technology that has gone through 2,400 hours of International Space Station on-orbit use between 2013 and 2016. While the Amine Swingbed is currently an experimental payload system, the Amine Swingbed may be converted to system hardware. If the Amine Swingbed becomes system hardware, it will supplement the Carbon Dioxide Removal Assembly (CDRA) as the primary CO2 removal technology on the International Space Station. NASA is also considering using the Amine Swingbed as the primary carbon dioxide removal technology for future extravehicular mobility units and for the Orion, which will be used for the Asteroid Redirect and Journey to Mars missions. The qualitative component of the reliability and maintainability analysis is a Failure Modes and Effects Analysis (FMEA). In the FMEA, I have investigated how individual components in the Amine Swingbed may fail, and what the worst case scenario is should a failure occur. The significant failure effects are the loss of ability to remove carbon dioxide, the formation of ammonia due to chemical degradation of the amine, and loss of atmosphere because the Amine Swingbed uses the vacuum of space to regenerate the Amine Swingbed. In the quantitative component of the reliability and maintainability analysis, I have assumed a constant failure rate for both electronic and nonelectronic parts. Using this data, I have created a Poisson distribution to predict the failure rate of the Amine Swingbed as a whole. I have determined a mean time to failure for the Amine Swingbed to be approximately 1,400 hours. The observed mean time to failure for the system is between 600 and 1,200 hours. This range includes initial testing of the Amine Swingbed, as well as software faults that are understood to be non-critical. If many of the commercial parts were switched to military-grade parts, the expected mean time to failure would be 2,300 hours. Both calculated mean times to failure for the Amine Swingbed use conservative failure rate models. The observed mean time to failure for CDRA is 2,500 hours. Working on this project and for NASA in general has helped me gain insight into current aeronautics missions, reliability engineering, circuit analysis, and different cultures. Prior my internship, I did not have a lot knowledge about the work being performed at NASA. As a chemical engineer, I had not really considered working for NASA as a career path. By engaging in interactions with civil servants, contractors, and other interns, I have learned a great deal about modern challenges that NASA is addressing. My work has helped me develop a knowledge base in safety and reliability that would be difficult to find elsewhere. Prior to this internship, I had not thought about reliability engineering. Now, I have gained a skillset in performing reliability analyses, and understanding the inner workings of a large mechanical system. I have also gained experience in understanding how electrical systems work while I was analyzing the electrical components of the Amine Swingbed. I did not expect to be exposed to as many different cultures as I have while working at NASA. I am referring to both within NASA and the Houston area. NASA employs individuals with a broad range of backgrounds. It has been great to learn from individuals who have highly diverse experiences and outlooks on the world. In the Houston area, I have come across individuals from different parts of the world. Interacting with such a high number of individuals with significantly different backgrounds has helped me to grow as a person in ways that I did not expect. My time at NASA has opened a window into the field of aeronautics. After earning a bachelor's degree in chemical engineering, I plan to go to graduate school for a PhD in engineering. Prior to coming to NASA, I was not aware of the graduate Pathways program. I intend to apply for the graduate Pathways program as positions are opened up. I would like to pursue future opportunities with NASA, especially as my engineering career progresses.

Simulating the Impact Response of Composite Airframe Components

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Littell, Justin D.; Fasanella, Edwin L.

2014-01-01

In 2010, NASA Langley Research Center obtained residual hardware from the US Army's Survivable Affordable Repairable Airframe Program (SARAP). The hardware consisted of a composite fuselage section that was representative of the center section of a Black Hawk helicopter. The section was fabricated by Sikorsky Aircraft Corporation and designated the Test Validation Article (TVA). The TVA was subjected to a vertical drop test in 2008 to evaluate a tilting roof concept to limit the intrusion of overhead mass items, such as the rotor transmission, into the fuselage cabin. As a result of the 2008 test, damage to the hardware was limited primarily to the roof. Consequently, when the post-test article was obtained in 2010, the roof area was removed and the remaining structure was cut into six different types of test specimens including: (1) tension and compression coupons for material property characterization, (2) I-beam sections, (3) T-sections, (4) cruciform sections, (5) a large subfloor section, and (6) a forward framed fuselage section. In 2011, NASA and Sikorsky entered into a cooperative research agreement to study the impact responses of composite airframe structures and to evaluate the capabilities of the explicit transient dynamic finite element code, LS-DYNA®, to simulate these responses including damage initiation and progressive failure. Finite element models of the composite specimens were developed and impact simulations were performed. The properties of the composite material were represented using both a progressive in-plane damage model (Mat 54) and a continuum damage mechanics model (Mat 58) in LS-DYNA. This paper provides test-analysis comparisons of time history responses and the location and type of damage for representative I-beam, T-section, and cruciform section components.

Energy efficient engine low-pressure compressor component test hardware detailed design report

NASA Technical Reports Server (NTRS)

Michael, C. J.; Halle, J. E.

1981-01-01

The aerodynamic and mechanical design description of the low pressure compressor component of the Energy Efficient Engine were used. The component was designed to meet the requirements of the Flight Propulsion System while maintaining a low cost approach in providing a low pressure compressor design for the Integrated Core/Low Spool test required in the Energy Efficient Engine Program. The resulting low pressure compressor component design meets or exceeds all design goals with the exception of surge margin. In addition, the expense of hardware fabrication for the Integrated Core/Low Spool test has been minimized through the use of existing minor part hardware.

Independent Orbiter Assessment (IOA): Analysis of the Electrical Power Distribution and Control Subsystem, Volume 2

NASA Technical Reports Server (NTRS)

Schmeckpeper, K. R.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Electrical Power Distribution and Control (EPD and C) hardware. The EPD and C hardware performs the functions of distributing, sensing, and controlling 28 volt DC power and of inverting, distributing, sensing, and controlling 117 volt 400 Hz AC power to all Orbiter subsystems from the three fuel cells in the Electrical Power Generation (EPG) subsystem. Volume 2 continues the presentation of IOA analysis worksheets and contains the potential critical items list.

Digital avionics design and reliability analyzer

NASA Technical Reports Server (NTRS)

1981-01-01

The description and specifications for a digital avionics design and reliability analyzer are given. Its basic function is to provide for the simulation and emulation of the various fault-tolerant digital avionic computer designs that are developed. It has been established that hardware emulation at the gate-level will be utilized. The primary benefit of emulation to reliability analysis is the fact that it provides the capability to model a system at a very detailed level. Emulation allows the direct insertion of faults into the system, rather than waiting for actual hardware failures to occur. This allows for controlled and accelerated testing of system reaction to hardware failures. There is a trade study which leads to the decision to specify a two-machine system, including an emulation computer connected to a general-purpose computer. There is also an evaluation of potential computers to serve as the emulation computer.

A systems approach to solder joint fatigue in spacecraft electronic packaging

NASA Technical Reports Server (NTRS)

Ross, R. G., Jr.

1991-01-01

Differential expansion induced fatigue resulting from temperature cycling is a leading cause of solder joint failures in spacecraft. Achieving high reliability flight hardware requires that each element of the fatigue issue be addressed carefully. This includes defining the complete thermal-cycle environment to be experienced by the hardware, developing electronic packaging concepts that are consistent with the defined environments, and validating the completed designs with a thorough qualification and acceptance test program. This paper describes a useful systems approach to solder fatigue based principally on the fundamental log-strain versus log-cycles-to-failure behavior of fatigue. This fundamental behavior has been useful to integrate diverse ground test and flight operational thermal-cycle environments into a unified electronics design approach. Each element of the approach reflects both the mechanism physics that control solder fatigue, as well as the practical realities of the hardware build, test, delivery, and application cycle.

Procedure for Failure Mode, Effects, and Criticality Analysis (FMECA)

NASA Technical Reports Server (NTRS)

1966-01-01

This document provides guidelines for the accomplishment of Failure Mode, Effects, and Criticality Analysis (FMECA) on the Apollo program. It is a procedure for analysis of hardware items to determine those items contributing most to system unreliability and crew safety problems.

ISS Fiber Optic Failure Investigation Root Cause Report

NASA Technical Reports Server (NTRS)

Leidecker, Henning; Plante, Jeannette

2000-01-01

In August of 1999, Boeing Corporation (Boeing) engineers began investigating failures of optical fiber being used on International Space Station flight hardware. Catastrophic failures of the fiber were linked to a defect in the glass fiber. Following several meetings of Boeing and NASA engineers and managers, Boeing created and led an investigation team, which examined the reliability of the cable installed in the U.S. Lab. NASA Goddard Space Flight Center's Components Technologies and Radiation Effects Branch (GSFC) led a team investigating the root cause of the failures. Information was gathered from: regular telecons and other communications with the investigation team, investigative trips to the cable distributor's plant, the cable manufacturing plant and the fiber manufacturing plant (including a review of build records), destructive and non-destructive testing, and expertise supplied by scientists from Dupont, and Lucent-Bell Laboratories. Several theories were established early on which were not able to completely address the destructive physical analysis and experiential evidence. Lucent suggested hydrofluoric acid (HF) etching of the glass and successfully duplicated the "rocket engine" defect. Strength testing coupled with examination of the low strength break sites linked features in the polyimide coating with latent defect sites. The information provided below explains what was learned about the susceptibility of the pre-cabled fiber to failure when cabled as it was for Space Station and the nature of the latent defects.

Application of IUS equipment and experience to orbit transfer vehicles of the 90's

NASA Astrophysics Data System (ADS)

Bangsund, E.; Keeney, J.; Cowgill, E.

1985-10-01

This paper relates experiences with the IUS program and the application of that experience to Future Orbit Transfer Vehicles. More specifically it includes the implementation of the U.S. Air Force Space Division high reliability parts standard (SMASO STD 73-2C) and the component/system test standard (MIL-STD-1540A). Test results from the parts and component level testing and the resulting system level test program for fourteen IUS flight vehicles are discussed. The IUS program has had the highest compliance with these standards and thus offers a benchmark of experience for future programs demanding extreme reliability. In summary, application of the stringent parts standard has resulted in fewer failures during testing and the stringent test standard has eliminated design problems in the hardware. Both have been expensive in costs and schedules, and should be applied with flexibility.

Stretchable electronics based on Ag-PDMS composites

PubMed Central

Larmagnac, Alexandre; Eggenberger, Samuel; Janossy, Hanna; Vörös, Janos

2014-01-01

Patterned structures of flexible, stretchable, electrically conductive materials on soft substrates could lead to novel electronic devices with unique mechanical properties allowing them to bend, fold, stretch or conform to their environment. For the last decade, research on improving the stretchability of circuits on elastomeric substrates has made significant progresses but designing printed circuit assemblies on elastomers remains challenging. Here we present a simple, cost-effective, cleanroom-free process to produce large scale soft electronic hardware where standard surface-mounted electrical components were directly bonded onto all-elastomeric printed circuit boards, or soft PCBs. Ag-PDMS tracks were stencil printed onto a PDMS substrate and soft PCBs were made by bonding the top and bottom layers together and filling punched holes with Ag-PDMS to create vias. Silver epoxy was used to bond commercial electrical components and no mechanical failure was observed after hundreds of stretching cycles. We also demonstrate the fabrication of a stretchable clock generator. PMID:25434843

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR). Version 3.5, Quick Reference Guide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilbert, B.G.; Richards, R.E.; Reece, W.J.

1992-10-01

This Reference Guide contains instructions on how to install and use Version 3.5 of the NRC-sponsored Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR). The NUCLARR data management system is contained in compressed files on the floppy diskettes that accompany this Reference Guide. NUCLARR is comprised of hardware component failure data (HCFD) and human error probability (HEP) data, both of which are available via a user-friendly, menu driven retrieval system. The data may be saved to a file in a format compatible with IRRAS 3.0 and commercially available statistical packages, or used to formulate log-plots and reports of data retrievalmore » and aggregation findings.« less

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilbert, B.G.; Richards, R.E.; Reece, W.J.

1992-10-01

This Reference Guide contains instructions on how to install and use Version 3.5 of the NRC-sponsored Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR). The NUCLARR data management system is contained in compressed files on the floppy diskettes that accompany this Reference Guide. NUCLARR is comprised of hardware component failure data (HCFD) and human error probability (HEP) data, both of which are available via a user-friendly, menu driven retrieval system. The data may be saved to a file in a format compatible with IRRAS 3.0 and commercially available statistical packages, or used to formulate log-plots and reports of data retrievalmore » and aggregation findings.« less

Fault Detection and Safety in Closed-Loop Artificial Pancreas Systems

PubMed Central

2014-01-01

Continuous subcutaneous insulin infusion pumps and continuous glucose monitors enable individuals with type 1 diabetes to achieve tighter blood glucose control and are critical components in a closed-loop artificial pancreas. Insulin infusion sets can fail and continuous glucose monitor sensor signals can suffer from a variety of anomalies, including signal dropout and pressure-induced sensor attenuations. In addition to hardware-based failures, software and human-induced errors can cause safety-related problems. Techniques for fault detection, safety analyses, and remote monitoring techniques that have been applied in other industries and applications, such as chemical process plants and commercial aircraft, are discussed and placed in the context of a closed-loop artificial pancreas. PMID:25049365

A Proposal for the Creation of a Diagnostics and Power Port Standard

NASA Technical Reports Server (NTRS)

Willeke, Thomas

2005-01-01

The contents of this paper discuss plans for communication failure due to lost hardware during Moon and Mars exploration missions. The author proposes a Diagnostics and Power Port (DPP) creation in the face of total communication failure. DDP would have a number of different power channels to replicate computer diagnostic abilities to find the root cause of failure.

Free-Swinging Failure Tolerance for Robotic Manipulators. Degree awarded by Purdue Univ.

NASA Technical Reports Server (NTRS)

English, James

1997-01-01

Under this GSRP fellowship, software-based failure-tolerance techniques were developed for robotic manipulators. The focus was on failures characterized by the loss of actuator torque at a joint, called free-swinging failures. The research results spanned many aspects of the free-swinging failure-tolerance problem, from preparing for an expected failure to discovery of postfailure capabilities to establishing efficient methods to realize those capabilities. Developed algorithms were verified using computer-based dynamic simulations, and these were further verified using hardware experiments at Johnson Space Center.

Independent Orbiter Assessment (IOA): Assessment of the reaction control system, volume 4

NASA Technical Reports Server (NTRS)

Prust, Chet D.; Hartman, Dan W.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the aft and forward Reaction Control System (RCS) hardware and Electrical Power Distribution and Control (EPD and C), generating draft failure modes and potential critical items. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline. This report documents the results of that comparison for the Orbiter RCS hardware and EPD and C systems. Volume 4 continues the presentation of IOA worksheets and contains the potential critical items list.

Independent Orbiter Assessment (IOA): Assessment of the nose wheel steering subsystem

NASA Technical Reports Server (NTRS)

Mediavilla, Anthony Scott

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Nose Wheel Steering (NWS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed NASA post 51-L FMEA/CIL baseline. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter NWS hardware.

Task Decomposition in Human Reliability Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boring, Ronald Laurids; Joe, Jeffrey Clark

2014-06-01

In the probabilistic safety assessments (PSAs) used in the nuclear industry, human failure events (HFEs) are determined as a subset of hardware failures, namely those hardware failures that could be triggered by human action or inaction. This approach is top-down, starting with hardware faults and deducing human contributions to those faults. Elsewhere, more traditionally human factors driven approaches would tend to look at opportunities for human errors first in a task analysis and then identify which of those errors is risk significant. The intersection of top-down and bottom-up approaches to defining HFEs has not been carefully studied. Ideally, both approachesmore » should arrive at the same set of HFEs. This question remains central as human reliability analysis (HRA) methods are generalized to new domains like oil and gas. The HFEs used in nuclear PSAs tend to be top-down— defined as a subset of the PSA—whereas the HFEs used in petroleum quantitative risk assessments (QRAs) are more likely to be bottom-up—derived from a task analysis conducted by human factors experts. The marriage of these approaches is necessary in order to ensure that HRA methods developed for top-down HFEs are also sufficient for bottom-up applications.« less

ISS Regenerative Life Support: Challenges and Success in the Quest for Long-Term Habitability in Space

NASA Technical Reports Server (NTRS)

Bazley, Jesse A.

2011-01-01

This presentation will discuss the International Space Station s (ISS) Regenerative Environmental Control and Life Support System (ECLSS) operations with discussion of the on-orbit lessons learned, specifically regarding the challenges that have been faced as the system has expanded with a growing ISS crew. Over the 10 year history of the ISS, there have been numerous challenges, failures, and triumphs in the quest to keep the crew alive and comfortable. Successful operation of the ECLSS not only requires maintenance of the hardware, but also management of the station resources in case of hardware failure or missed re-supply. This involves effective communication between the primary International Partners (NASA and Roskosmos) and the secondary partners (JAXA and ESA) in order to keep a reserve of the contingency consumables and allow for re-supply of failed hardware. The ISS ECLSS utilizes consumables storage for contingency usage as well as longer-term regenerative systems, which allow for conservation of the expensive resources brought up by re-supply vehicles. This long-term hardware, and the interactions with software, was a challenge for Systems Engineers when they were designed and require multiple operational workarounds in order to function continuously. On a day-to-day basis, the ECLSS provides big challenges to the on console controllers. Main challenges involve the utilization of the resources that have been brought up by the visiting vehicles prior to undocking, balance of contributions between the International Partners for both systems and resources, and maintaining balance between the many interdependent systems, which includes providing the resources they need when they need it. The current biggest challenge for ECLSS is the Regenerative ECLSS system, which continuously recycles urine and condensate water into drinking water and oxygen. These systems were brought to full functionality on STS-126 (ULF-2) mission. Through system failures and recovery, the ECLSS console has learned how to balance the water within the systems, store and use water for contingencies, and continue to work with the International Partners for short-term failures. Through these challenges and the system failures, the most important lesson learned has been the importance of redundancy and operational workarounds. It is only because of the flexibility of the hardware and the software that flight controllers have the opportunity to continue operating the system as a whole for mission success.

Post-Shuttle EVA Operations on ISS

NASA Technical Reports Server (NTRS)

West, William; Witt, Vincent; Chullen, Cinda

2010-01-01

The expected retirement of the NASA Space Transportation System (also known as the Space Shuttle ) by 2011 will pose a significant challenge to Extra-Vehicular Activities (EVA) on-board the International Space Station (ISS). The EVA hardware currently used to assemble and maintain the ISS was designed assuming that it would be returned to Earth on the Space Shuttle for refurbishment, or if necessary for failure investigation. With the retirement of the Space Shuttle, a new concept of operations was developed to enable EVA hardware (Extra-vehicular Mobility Unit (EMU), Airlock Systems, EVA tools, and associated support hardware and consumables) to perform ISS EVAs until 2015, and possibly beyond to 2020. Shortly after the decision to retire the Space Shuttle was announced, the EVA 2010 Project was jointly initiated by NASA and the One EVA contractor team. The challenges addressed were to extend the operating life and certification of EVA hardware, to secure the capability to launch EVA hardware safely on alternate launch vehicles, to protect for EMU hardware operability on-orbit, and to determine the source of high water purity to support recharge of PLSSs (no longer available via Shuttle). EVA 2010 Project includes the following tasks: the development of a launch fixture that would allow the EMU Portable Life Support System (PLSS) to be launched on-board alternate vehicles; extension of the EMU hardware maintenance interval from 3 years (current certification) to a minimum of 6 years (to extend to 2015); testing of recycled ISS Water Processor Assembly (WPA) water for use in the EMU cooling system in lieu of water resupplied by International Partner (IP) vehicles; development of techniques to remove & replace critical components in the PLSS on-orbit (not routine); extension of on-orbit certification of EVA tools; and development of an EVA hardware logistical plan to support the ISS without the Space Shuttle. Assumptions for the EVA 2010 Project included no more than 8 EVAs per year for ISS EVA operations in the Post-Shuttle environment and limited availability of cargo upmass on IP launch vehicles. From 2010 forward, EVA operations on-board the ISS without the Space Shuttle will be a paradigm shift in safely operating EVA hardware on orbit and the EVA 2010 effort was initiated to accommodate this significant change in EVA evolutionary history. 1

System for Anomaly and Failure Detection (SAFD) system development

NASA Technical Reports Server (NTRS)

Oreilly, D.

1992-01-01

This task specified developing the hardware and software necessary to implement the System for Anomaly and Failure Detection (SAFD) algorithm, developed under Technology Test Bed (TTB) Task 21, on the TTB engine stand. This effort involved building two units; one unit to be installed in the Block II Space Shuttle Main Engine (SSME) Hardware Simulation Lab (HSL) at Marshall Space Flight Center (MSFC), and one unit to be installed at the TTB engine stand. Rocketdyne personnel from the HSL performed the task. The SAFD algorithm was developed as an improvement over the current redline system used in the Space Shuttle Main Engine Controller (SSMEC). Simulation tests and execution against previous hot fire tests demonstrated that the SAFD algorithm can detect engine failure as much as tens of seconds before the redline system recognized the failure. Although the current algorithm only operates during steady state conditions (engine not throttling), work is underway to expand the algorithm to work during transient condition.

Independent Orbiter Assessment (IOA): FMEA/CIL assessment

NASA Technical Reports Server (NTRS)

Saiidi, Mo J.; Swain, L. J.; Compton, J. M.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. Direction was given by the Orbiter and GFE Projects Office to perform the hardware analysis and assessment using the instructions and ground rules defined in NSTS 22206. The IOA analysis features a top-down approach to determine hardware failure modes, criticality, and potential critical items. To preserve independence, the anlaysis was accomplished without reliance upon the results contained within the NASA and prime contractor FMEA/CIL documentation. The assessment process compares the independently derived failure modes and criticality assignments to the proposed NASA Post 51-L FMEA/CIL documentation. When possible, assessment issues are discussed and resolved with the NASA subsystem managers. The assessment results for each subsystem are summarized. The most important Orbiter assessment finding was the previously unknown stuck autopilot push-button criticality 1/1 failure mode, having a worst case effect of loss of crew/vehicle when a microwave landing system is not active.

RHCV Telescope System Operations Manual

DTIC Science & Technology

2018-01-05

hardware and software components. Several of the components are closely coupled and rely on one-another, while others are largely independent. This...of hardware and software components. Several of the components are closely coupled and rely on one-another, while others are largely independent. This...attendant training The use cases are briefly described in separate sections, and step-by-step instructions are presented. Each section begins on a new

Guidelines for Proof Test Analysis

NASA Technical Reports Server (NTRS)

Chell, G. G.; McClung, R. C.; Kuhlman, C. J.; Russell, D. A.; Garr, K.; Donnelly, B.

1999-01-01

These guidelines integrate state-of-the-art elastic-plastic fracture mechanics (EPFM) and proof test implementation issues into a comprehensive proof test analysis procedure in the form of a road map which identifies the types of data, fracture mechanics based parameters, and calculations needed to perform flaw screening and minimum proof load analyses of fracture critical components. Worked examples are presented to illustrate the application of the road map to proof test analysis. The state-of-the art fracture technology employed in these guidelines is based on the EPFM parameter, J, and a pictorial representation of a J fracture analysis, called the failure assessment diagram (FAD) approach. The recommended fracture technology is validated using finite element J results, and laboratory and hardware fracture test results on the nickel-based superalloy Inconel 718, the aluminum alloy 2024-T3511, and ferritic pressure vessel steels. In all cases the laboratory specimens and hardware failed by ductile mechanisms. Advanced proof test analyses involving probability analysis and multiple-cycle proof testing (MCPT) are addressed. Finally, recommendations are provided on how to account for the effects of the proof test overload on subsequent service fatigue and fracture behaviors.

Orthos, an alarm system for the ALICE DAQ operations

NASA Astrophysics Data System (ADS)

Chapeland, Sylvain; Carena, Franco; Carena, Wisla; Chibante Barroso, Vasco; Costa, Filippo; Denes, Ervin; Divia, Roberto; Fuchs, Ulrich; Grigore, Alexandru; Simonetti, Giuseppe; Soos, Csaba; Telesca, Adriana; Vande Vyvre, Pierre; von Haller, Barthelemy

2012-12-01

ALICE (A Large Ion Collider Experiment) is the heavy-ion detector studying the physics of strongly interacting matter and the quark-gluon plasma at the CERN LHC (Large Hadron Collider). The DAQ (Data Acquisition System) facilities handle the data flow from the detectors electronics up to the mass storage. The DAQ system is based on a large farm of commodity hardware consisting of more than 600 devices (Linux PCs, storage, network switches), and controls hundreds of distributed hardware and software components interacting together. This paper presents Orthos, the alarm system used to detect, log, report, and follow-up abnormal situations on the DAQ machines at the experimental area. The main objective of this package is to integrate alarm detection and notification mechanisms with a full-featured issues tracker, in order to prioritize, assign, and fix system failures optimally. This tool relies on a database repository with a logic engine, SQL interfaces to inject or query metrics, and dynamic web pages for user interaction. We describe the system architecture, the technologies used for the implementation, and the integration with existing monitoring tools.

Reliability achievement in high technology space systems

NASA Technical Reports Server (NTRS)

Lindstrom, D. L.

1981-01-01

The production of failure-free hardware is discussed. The elements required to achieve such hardware are: technical expertise to design, analyze, and fully understand the design; use of high reliability parts and materials control in the manufacturing process; and testing to understand the system and weed out defects. The durability of the Hughes family of satellites is highlighted.

Kinematic optimization of upgrade to the Hobby-Eberly Telescope through novel use of commercially available three-dimensional CAD package

NASA Astrophysics Data System (ADS)

Wedeking, Gregory A.; Zierer, Joseph J.; Jackson, John R.

2010-07-01

The University of Texas, Center for Electromechanics (UT-CEM) is making a major upgrade to the robotic tracking system on the Hobby Eberly Telescope (HET) as part of theWide Field Upgrade (WFU). The upgrade focuses on a seven-fold increase in payload and necessitated a complete redesign of all tracker supporting structure and motion control systems, including the tracker bridge, ten drive systems, carriage frames, a hexapod, and many other subsystems. The cost and sensitivity of the scientific payload, coupled with the tracker system mass increase, necessitated major upgrades to personnel and hardware safety systems. To optimize kinematic design of the entire tracker, UT-CEM developed novel uses of constraints and drivers to interface with a commercially available CAD package (SolidWorks). For example, to optimize volume usage and minimize obscuration, the CAD software was exercised to accurately determine tracker/hexapod operational space needed to meet science requirements. To verify hexapod controller models, actuator travel requirements were graphically measured and compared to well defined equations of motion for Stewart platforms. To ensure critical hardware safety during various failure modes, UT-CEM engineers developed Visual Basic drivers to interface with the CAD software and quickly tabulate distance measurements between critical pieces of optical hardware and adjacent components for thousands of possible hexapod configurations. These advances and techniques, applicable to any challenging robotic system design, are documented and describe new ways to use commercially available software tools to more clearly define hardware requirements and help insure safe operation.

Source Data Impacts on Epistemic Uncertainty for Launch Vehicle Fault Tree Models

NASA Technical Reports Server (NTRS)

Al Hassan, Mohammad; Novack, Steven; Ring, Robert

2016-01-01

Launch vehicle systems are designed and developed using both heritage and new hardware. Design modifications to the heritage hardware to fit new functional system requirements can impact the applicability of heritage reliability data. Risk estimates for newly designed systems must be developed from generic data sources such as commercially available reliability databases using reliability prediction methodologies, such as those addressed in MIL-HDBK-217F. Failure estimates must be converted from the generic environment to the specific operating environment of the system in which it is used. In addition, some qualification of applicability for the data source to the current system should be made. Characterizing data applicability under these circumstances is crucial to developing model estimations that support confident decisions on design changes and trade studies. This paper will demonstrate a data-source applicability classification method for suggesting epistemic component uncertainty to a target vehicle based on the source and operating environment of the originating data. The source applicability is determined using heuristic guidelines while translation of operating environments is accomplished by applying statistical methods to MIL-HDK-217F tables. The paper will provide one example for assigning environmental factors uncertainty when translating between operating environments for the microelectronic part-type components. The heuristic guidelines will be followed by uncertainty-importance routines to assess the need for more applicable data to reduce model uncertainty.

Age Life Evaluation of Space Shuttle Crew Escape System Pyrotechnic Components Loaded with Hexanitrostilbene (HNS)

NASA Technical Reports Server (NTRS)

Hoffman, William C., III

1996-01-01

Determining deterioration characteristics of the Space Shuttle crew escape system pyrotechnic components loaded with hexanitrostilbene would enable us to establish a hardware life-limit for these items, so we could better plan our equipment use and, possibly, extend the useful life of the hardware. We subjected components to accelerated-age environments to determine degradation characteristics and established a hardware life-limit based upon observed and calculated trends. We extracted samples using manufacturing lots currently installed in the Space Shuttle crew escape system and from other NASA programs. Hardware included in the study consisted of various forms and ages of mild detonating fuse, linear shaped charge, and flexible confined detonating cord. The hardware types were segregated into 5 groups. One was subjected to detonation velocity testing for a baseline. Two were first subjected to prolonged 155 F heat exposure, and the other two were first subjected to 255 F, before undergoing detonation velocity testing and/or chromatography analysis. Test results showed no measurable changes in performance to allow a prediction of an end of life given the storage and elevated temperature environments the hardware experiences. Given the lack of a definitive performance trend, coupled with previous tests on post-flight Space Shuttle hardware showing no significant changes in chemical purity or detonation velocity, we recommend a safe increase in the useful life of the hardware to 20 years, from the current maximum limits of 10 and 15 years, depending on the hardware.

Evolutionary online behaviour learning and adaptation in real robots

PubMed Central

Correia, Luís; Christensen, Anders Lyhne

2017-01-01

Online evolution of behavioural control on real robots is an open-ended approach to autonomous learning and adaptation: robots have the potential to automatically learn new tasks and to adapt to changes in environmental conditions, or to failures in sensors and/or actuators. However, studies have so far almost exclusively been carried out in simulation because evolution in real hardware has required several days or weeks to produce capable robots. In this article, we successfully evolve neural network-based controllers in real robotic hardware to solve two single-robot tasks and one collective robotics task. Controllers are evolved either from random solutions or from solutions pre-evolved in simulation. In all cases, capable solutions are found in a timely manner (1 h or less). Results show that more accurate simulations may lead to higher-performing controllers, and that completing the optimization process in real robots is meaningful, even if solutions found in simulation differ from solutions in reality. We furthermore demonstrate for the first time the adaptive capabilities of online evolution in real robotic hardware, including robots able to overcome faults injected in the motors of multiple units simultaneously, and to modify their behaviour in response to changes in the task requirements. We conclude by assessing the contribution of each algorithmic component on the performance of the underlying evolutionary algorithm. PMID:28791130

Design and Certification of the Extravehicular Activity Mobility Unit (EMU) Water Processing Jumper

NASA Technical Reports Server (NTRS)

Peterson, Laurie J.; Neumeyer, Derek J.; Lewis, John F.

2006-01-01

The Extravehicular Mobility Units (EMUs) onboard the International Space Station (ISS) experienced a failure due to cooling water contamination from biomass and corrosion byproducts forming solids around the EMU pump rotor. The coolant had no biocide and a low pH which induced biofilm growth and corrosion precipitates, respectively. NASA JSC was tasked with building hardware to clean the ionic, organic, and particulate load from the EMU coolant loop before and after Extravehicular Activity (EVAs). Based on a return sample of the EMU coolant loop, the chemical load was well understood, but there was not sufficient volume of the returned sample to analyze particulates. Through work with EMU specialists, chemists, (EVA) Mission Operations Directorate (MOD) representation, safety and mission assurance, astronaut crew, and team engineers, requirements were developed for the EMU Water Processing hardware (sometimes referred to as the Airlock Coolant Loop Recovery [A/L CLR] system). Those requirements ranged from the operable level of ionic, organic, and particulate load, interfaces to the EMU, maximum cycle time, operating pressure drop, flow rate, and temperature, leakage rates, and biocide levels for storage. Design work began in February 2005 and certification was completed in April 2005 to support a return to flight launch date of May 12, 2005. This paper will discuss the details of the design and certification of the EMU Water Processing hardware and its components

The (human) science of medical virtual learning environments.

PubMed

Stone, Robert J

2011-01-27

The uptake of virtual simulation technologies in both military and civilian surgical contexts has been both slow and patchy. The failure of the virtual reality community in the 1990s and early 2000s to deliver affordable and accessible training systems stems not only from an obsessive quest to develop the 'ultimate' in so-called 'immersive' hardware solutions, from head-mounted displays to large-scale projection theatres, but also from a comprehensive lack of attention to the needs of the end users. While many still perceive the science of simulation to be defined by technological advances, such as computing power, specialized graphics hardware, advanced interactive controllers, displays and so on, the true science underpinning simulation--the science that helps to guarantee the transfer of skills from the simulated to the real--is that of human factors, a well-established discipline that focuses on the abilities and limitations of the end user when designing interactive systems, as opposed to the more commercially explicit components of technology. Based on three surgical simulation case studies, the importance of a human factors approach to the design of appropriate simulation content and interactive hardware for medical simulation is illustrated. The studies demonstrate that it is unnecessary to pursue real-world fidelity in all instances in order to achieve psychological fidelity--the degree to which the simulated tasks reproduce and foster knowledge, skills and behaviours that can be reliably transferred to real-world training applications.

49 CFR Appendix A to Part 238 - Schedule of Civil Penalties 1

Code of Federal Regulations, 2014 CFR

2014-10-01

....15Movement of power brake defects: (b) Improper movement from Class I or IA brake test 5,000 7,500 (c... required design features 5,000 7,500 (e) Failure to comply with hardware and software safety program 5,000... test previously used equipment 7,500 11,000 (b)(1) Failure to develop plan 7,500 11,000 (b)(2) Failure...

49 CFR Appendix A to Part 238 - Schedule of Civil Penalties 1

Code of Federal Regulations, 2010 CFR

2010-10-01

....15Movement of power brake defects: (b) Improper movement from Class I or IA brake test 5,000 7,500 (c... required design features 5,000 7,500 (e) Failure to comply with hardware and software safety program 5,000... test previously used equipment 7,500 11,000 (b)(1) Failure to develop plan 7,500 11,000 (b)(2) Failure...

49 CFR Appendix A to Part 238 - Schedule of Civil Penalties 1

Code of Federal Regulations, 2013 CFR

2013-10-01

... movement from Class I or IA brake test 5,000 7,500 (c) Improper movement of en route defect 2,500 5,000 (2...) Failure to include required design features 5,000 7,500 (e) Failure to comply with hardware and software... properly test previously used equipment 7,500 11,000 (b)(1) Failure to develop plan 7,500 11,000 (b)(2...

Hardware design for the Autonomous Visibility Monitoring (AVM) observatory

NASA Technical Reports Server (NTRS)

Cowles, K.

1993-01-01

The hardware for the three Autonomous Visibility Monitoring (AVM) observatories was redesigned. Changes in hardware design include electronics components, weather sensors, and the telescope drive system. Operation of the new hardware is discussed, as well as some of its features. The redesign will allow reliable automated operation.

Electro-Mechanical Systems for Extreme Space Environments

NASA Technical Reports Server (NTRS)

Mojarradi, Mohammad M.; Tyler, Tony R.; Abel, Phillip B.; Levanas, Greg

2011-01-01

Exploration beyond low earth orbit presents challenges for hardware that must operate in extreme environments. The current state of the art is to isolate and provide heating for sensitive hardware in order to survive. However, this protection results in penalties of weight and power for the spacecraft. This is particularly true for electro-mechanical based technology such as electronics, actuators and sensors. Especially when considering distributed electronics, many electro-mechanical systems need to be located in appendage type locations, making it much harder to protect from the extreme environments. The purpose of this paper to describe the advances made in the area of developing electro-mechanical technology to survive these environments with minimal protection. The Jet Propulsion Lab (JPL), the Glenn Research Center (GRC), the Langley Research Center (LaRC), and Aeroflex, Inc. over the last few years have worked to develop and test electro-mechanical hardware that will meet the stringent environmental demands of the moon, and which can also be leveraged for other challenging space exploration missions. Prototype actuators and electronics have been built and tested. Brushless DC actuators designed by Aeroflex, Inc have been tested with interface temperatures as low as 14 degrees Kelvin. Testing of the Aeroflex design has shown that a brushless DC motor with a single stage planetary gearbox can operate in low temperature environments for at least 120 million cycles (measured at motor) if long life is considered as part of the design. A motor control distributed electronics concept developed by JPL was built and operated at temperatures as low as -160 C, with many components still operational down to -245 C. Testing identified the components not capable of meeting the low temperature goal of -230 C. This distributed controller is universal in design with the ability to control different types of motors and read many different types of sensors. The controller form factor was designed to surround or be at the actuator. Communication with the slave controllers is accomplished by a bus, thus limiting the number of wires that must be routed to the extremity locations. Efforts have also been made to increase the power capability of these electronics for the ability to power and control actuators up to 2.5KW and still meet the environmental challenges. For commutation and control of the actuator, a resolver was integrated and tested with the actuator. Testing of this resolver demonstrated temperature limitations. Subsequent failure analysis isolated the low temperature failure mechanism and a design solution was negotiated with the manufacturer. Several years of work have resulted in specialized electro-mechanical hardware to meet extreme space exploration environments, a test history that verifies and finds limitations of the designs and a growing knowledge base that can be leveraged by future space exploration missions.

NASA Operational Simulator for Small Satellites: Tools for Software Based Validation and Verification of Small Satellites

NASA Technical Reports Server (NTRS)

Grubb, Matt

2016-01-01

The NASA Operational Simulator for Small Satellites (NOS3) is a suite of tools to aid in areas such as software development, integration test (IT), mission operations training, verification and validation (VV), and software systems check-out. NOS3 provides a software development environment, a multi-target build system, an operator interface-ground station, dynamics and environment simulations, and software-based hardware models. NOS3 enables the development of flight software (FSW) early in the project life cycle, when access to hardware is typically not available. For small satellites there are extensive lead times on many of the commercial-off-the-shelf (COTS) components as well as limited funding for engineering test units (ETU). Considering the difficulty of providing a hardware test-bed to each developer tester, hardware models are modeled based upon characteristic data or manufacturers data sheets for each individual component. The fidelity of each hardware models is such that FSW executes unaware that physical hardware is not present. This allows binaries to be compiled for both the simulation environment, and the flight computer, without changing the FSW source code. For hardware models that provide data dependent on the environment, such as a GPS receiver or magnetometer, an open-source tool from NASA GSFC (42 Spacecraft Simulation) is used to provide the necessary data. The underlying infrastructure used to transfer messages between FSW and the hardware models can also be used to monitor, intercept, and inject messages, which has proven to be beneficial for VV of larger missions such as James Webb Space Telescope (JWST). As hardware is procured, drivers can be added to the environment to enable hardware-in-the-loop (HWIL) testing. When strict time synchronization is not vital, any number of combinations of hardware components and software-based models can be tested. The open-source operator interface used in NOS3 is COSMOS from Ball Aerospace. For testing, plug-ins are implemented in COSMOS to control the NOS3 simulations, while the command and telemetry tools available in COSMOS are used to communicate with FSW. NOS3 is actively being used for FSW development and component testing of the Simulation-to-Flight 1 (STF-1) CubeSat. As NOS3 matures, hardware models have been added for common CubeSat components such as Novatel GPS receivers, ClydeSpace electrical power systems and batteries, ISISpace antenna systems, etc. In the future, NASA IVV plans to distribute NOS3 to other CubeSat developers and release the suite to the open-source community.

Orbiter wheel and tire certification

NASA Technical Reports Server (NTRS)

Campbell, C. C., Jr.

1985-01-01

The orbiter wheel and tire development has required a unique series of certification tests to demonstrate the ability of the hardware to meet severe performance requirements. Early tests of the main landing gear wheel using conventional slow roll testing resulted in hardware failures. This resulted in a need to conduct high velocity tests with crosswind effects for assurance that the hardware was safe for a limited number of flights. Currently, this approach and the conventional slow roll and static tests are used to certify the wheel/tire assembly for operational use.

Post-Shuttle EVA Operations on ISS

NASA Technical Reports Server (NTRS)

West, Bill; Witt, Vincent; Chullen, Cinda

2010-01-01

The EVA hardware used to assemble and maintain the ISS was designed with the assumption that it would be returned to Earth on the Space Shuttle for ground processing, refurbishment, or failure investigation (if necessary). With the retirement of the Space Shuttle, a new concept of operations was developed to enable EVA hardware (EMU, Airlock Systems, EVA tools, and associated support equipment and consumables) to perform ISS EVAs until 2016 and possibly beyond to 2020. Shortly after the decision to retire the Space Shuttle was announced, NASA and the One EVA contractor team jointly initiated the EVA 2010 Project. Challenges were addressed to extend the operating life and certification of EVA hardware, secure the capability to launch EVA hardware safely on alternate launch vehicles, and protect EMU hardware operability on orbit for long durations.

Turbofan engine demonstration of sensor failure detection

NASA Technical Reports Server (NTRS)

Merrill, Walter C.; Delaat, John C.; Abdelwahab, Mahmood

1991-01-01

In the paper, the results of a full-scale engine demonstration of a sensor failure detection algorithm are presented. The algorithm detects, isolates, and accommodates sensor failures using analytical redundancy. The experimental hardware, including the F100 engine, is described. Demonstration results were obtained over a large portion of a typical flight envelope for the F100 engine. They include both subsonic and supersonic conditions at both medium and full, nonafter burning, power. Estimated accuracy, minimum detectable levels of sensor failures, and failure accommodation performance for an F100 turbofan engine control system are discussed.

Distributed phased array architecture study

NASA Technical Reports Server (NTRS)

Bourgeois, Brian

1987-01-01

Variations in amplifiers and phase shifters can cause degraded antenna performance, depending also on the environmental conditions and antenna array architecture. The implementation of distributed phased array hardware was studied with the aid of the DISTAR computer program as a simulation tool. This simulation provides guidance in hardware simulation. Both hard and soft failures of the amplifiers in the T/R modules are modeled. Hard failures are catastrophic: no power is transmitted to the antenna elements. Noncatastrophic or soft failures are modeled as a modified Gaussian distribution. The resulting amplitude characteristics then determine the array excitation coefficients. The phase characteristics take on a uniform distribution. Pattern characteristics such as antenna gain, half power beamwidth, mainbeam phase errors, sidelobe levels, and beam pointing errors were studied as functions of amplifier and phase shifter variations. General specifications for amplifier and phase shifter tolerances in various architecture configurations for C band and S band were determined.

Independent Orbiter Assessment (IOA): Assessment of the active thermal control system

NASA Technical Reports Server (NTRS)

Sinclair, S. K.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Active Thermal Control System (ATCS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the available NASA FMEA/CIL data. Discrepancies from the comparison were documented, and where enough information was available, recommendations for resolution of the discrepancies were made. This report documents the results of that comparison for the Orbiter ATCS hardware. The IOA product for the ATCS independent analysis consisted of 310 failure mode worksheets that resulted in 101 potential critical items (PCI) being identified. A comparison was made to the available NASA data which consisted of 252 FMEAs and 109 CIL items.

Man-rated flight software for the F-8 DFBW program

NASA Technical Reports Server (NTRS)

Bairnsfather, R. R.

1975-01-01

The design, implementation, and verification of the flight control software used in the F-8 DFBW program are discussed. Since the DFBW utilizes an Apollo computer and hardware, the procedures, controls, and basic management techniques employed are based on those developed for the Apollo software system. Program Assembly Control, simulator configuration control, erasable-memory load generation, change procedures and anomaly reporting are discussed. The primary verification tools--the all-digital simulator, the hybrid simulator, and the Iron Bird simulator--are described, as well as the program test plans and their implementation on the various simulators. Failure-effects analysis and the creation of special failure-generating software for testing purposes are described. The quality of the end product is evidenced by the F-8 DFBW flight test program in which 42 flights, totaling 58 hours of flight time, were successfully made without any DFCS inflight software, or hardware, failures.

Independent Orbiter Assessment (IOA): Assessment of the crew equipment subsystem

NASA Technical Reports Server (NTRS)

Saxon, H.; Richard, Bill; Sinclair, S. K.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Crew Equipment hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter Crew Equipment hardware. The IOA product for the Crew Equipment analysis consisted of 352 failure mode worksheets that resulted in 78 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 351 FMEAs and 82 CIL items.

ARC-2007-ACD07-0073-126

NASA Image and Video Library

2007-08-07

LCROSS flight hardware in clean room at Ames N-240. EEL personnel fabricating testing components with Jerry Wang of Ames, Engineering Evaluation labLCROSS flight hardware in clean room at Ames N-240. EEL personnel fabricating testing components with Jerry Wang of Ames, Engineering Evaluation lab

Independent Orbiter Assessment (IOA): Assessment of the reaction control system, volume 5

NASA Technical Reports Server (NTRS)

Prust, Chet D.; Hartman, Dan W.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the aft and forward Reaction Control System (RCS) hardware and Electrical Power Distribution and Control (EPD and C), generating draft failure modes and potential critical items. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline. This report documents the results of that comparison for the Orbiter RCS hardware and EPD and C systems. Volume 5 contains detailed analysis and superseded analysis worksheets and the NASA FMEA to IOA worksheet cross reference and recommendations.

Independent Orbiter Assessment (IOA): Assessment of the communication and tracking subsystem, volume 3

NASA Technical Reports Server (NTRS)

Long, W. C.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed and analysis of the Communication and Tracking hardware, generating draft failure modes and potential critical items. The IOA results were then compared to the NASA FMEA/CIL baseline. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter Communication and Tracking hardware. Volume 3 continues the presentation of IOA worksheets and contains the potential critical items list, detailed analysis, and the NASA FMEA to IOA worksheet cross reference and recommendations.

Independent Orbiter Assessment (IOA): Assessment of the extravehicular mobility unit, volume 1

NASA Technical Reports Server (NTRS)

Raffaelli, Gary G.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort performed an independent analysis of the Extravehicular Mobility Unit (EMU) hardware and system, generating draft failure modes criticalities and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were than compared to the most recent proposed Post 51-L NASA FMEA/CIL baseline. A resolution of each discrepancy from the comparison was provided through additional analysis as required. This report documents the results of that comparison for the Orbiter EMU hardware.

Independent Orbiter Assessment (IOA): Assessment of the data processing system FMEA/CIL

NASA Technical Reports Server (NTRS)

Lowery, H. J.; Haufler, W. A.

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Data Processing System (DPS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. The results of that comparison is documented for the Orbiter DPS hardware.

Design of a nickel-hydrogen battery simulator for the NASA EOS testbed

NASA Technical Reports Server (NTRS)

Gur, Zvi; Mang, Xuesi; Patil, Ashok R.; Sable, Dan M.; Cho, Bo H.; Lee, Fred C.

1992-01-01

The hardware and software design of a nickel-hydrogen (Ni-H2) battery simulator (BS) with application to the NASA Earth Observation System (EOS) satellite is presented. The battery simulator is developed as a part of a complete testbed for the EOS satellite power system. The battery simulator involves both hardware and software components. The hardware component includes the capability of sourcing and sinking current at a constant programmable voltage. The software component includes the capability of monitoring the battery's ampere-hours (Ah) and programming the battery voltage according to an empirical model of the nickel-hydrogen battery stored in a computer.

Study of a unified hardware and software fault-tolerant architecture

NASA Technical Reports Server (NTRS)

Lala, Jaynarayan; Alger, Linda; Friend, Steven; Greeley, Gregory; Sacco, Stephen; Adams, Stuart

1989-01-01

A unified architectural concept, called the Fault Tolerant Processor Attached Processor (FTP-AP), that can tolerate hardware as well as software faults is proposed for applications requiring ultrareliable computation capability. An emulation of the FTP-AP architecture, consisting of a breadboard Motorola 68010-based quadruply redundant Fault Tolerant Processor, four VAX 750s as attached processors, and four versions of a transport aircraft yaw damper control law, is used as a testbed in the AIRLAB to examine a number of critical issues. Solutions of several basic problems associated with N-Version software are proposed and implemented on the testbed. This includes a confidence voter to resolve coincident errors in N-Version software. A reliability model of N-Version software that is based upon the recent understanding of software failure mechanisms is also developed. The basic FTP-AP architectural concept appears suitable for hosting N-Version application software while at the same time tolerating hardware failures. Architectural enhancements for greater efficiency, software reliability modeling, and N-Version issues that merit further research are identified.

15 CFR Supplement No. 6 to Part 742 - Technical Questionnaire for Encryption Items

Code of Federal Regulations, 2012 CFR

2012-01-01

... software, provide the following information: (1) Description of all the symmetric and asymmetric encryption... third-party hardware or software encryption components (if any). Identify the manufacturers of the hardware or software components, including specific part numbers and version information as needed to...

15 CFR Supplement No. 6 to Part 742 - Technical Questionnaire for Encryption Items

Code of Federal Regulations, 2013 CFR

2013-01-01

... software, provide the following information: (1) Description of all the symmetric and asymmetric encryption... third-party hardware or software encryption components (if any). Identify the manufacturers of the hardware or software components, including specific part numbers and version information as needed to...

15 CFR Supplement No. 6 to Part 742 - Technical Questionnaire for Encryption Items

Code of Federal Regulations, 2014 CFR

2014-01-01

... software, provide the following information: (1) Description of all the symmetric and asymmetric encryption... third-party hardware or software encryption components (if any). Identify the manufacturers of the hardware or software components, including specific part numbers and version information as needed to...

Improving the treatment planning and delivery process of Xoft electronic skin brachytherapy.

PubMed

Manger, Ryan; Rahn, Douglas; Hoisak, Jeremy; Dragojević, Irena

2018-05-14

To develop an improved Xoft electronic skin brachytherapy process and identify areas of further improvement. A multidisciplinary team conducted a failure modes and effects analysis (FMEA) by developing a process map and a corresponding list of failure modes. The failure modes were scored for their occurrence, severity, and detectability, and a risk priority number (RPN) was calculated for each failure mode as the product of occurrence, severity, and detectability. Corrective actions were implemented to address the higher risk failure modes, and a revised process was generated. The RPNs of the failure modes were compared between the initial process and final process to assess the perceived benefits of the corrective actions. The final treatment process consists of 100 steps and 114 failure modes. The FMEA took approximately 20 person-hours (one physician, three physicists, and two therapists) to complete. The 10 most dangerous failure modes had RPNs ranging from 336 to 630. Corrective actions were effective at addressing most failure modes (10 riskiest RPNs ranging from 189 to 310), yet the RPNs were higher than those published for alternative systems. Many of these high-risk failure modes remained due to hardware design limitations. FMEA helps guide process improvement efforts by emphasizing the riskiest steps. Significant risks are apparent when using a Xoft treatment unit for skin brachytherapy due to hardware limitations such as the lack of several interlocks, a short source lifespan, and variability in source output. The process presented in this article is expected to reduce but not eliminate these risks. Copyright © 2018 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

First metatarsophalangeal joint arthrodesis: an evaluation of hardware failure.

PubMed

Bennett, Gordon L; Kay, David B; Sabatta, James

2005-08-01

First metatarsophalangeal joint (MTPJ) arthrodesis is commonly used for the treatment of a variety of conditions affecting the hallux. We used a method incorporating a ball-and-cup preparation of the first metatarsal and proximal phalanx, followed by fixation of the arthrodesis with a lag screw and a dorsal plate (Synthes Modular Hand Set). Ninety-five consecutive patients had first MTPJ arthrodesis using fixation with the Synthes Modular Hand Set. All patients were evaluated preoperatively, at regular intervals postoperatively, and at final followup. The American Orthopaedic Foot and Ankle Society (AOFAS) forefoot scoring system was used preoperatively and at final followup. Solid fusion occurred in 93 of 107 feet (86.9%). In the 14 that did not fuse, either the screws or plate, or both, broke. Ten of the 14 feet were symptomatic, but only three required further operative treatment. There were no hardware problems or failures in patients who had solid fusions. Preoperative AOFAS scores were improved after surgery in all patients. A solid first MTPJ fusion results in excellent function and pain relief, but the Synthes Modular Hand Set implants do not appear to be strong enough in all patients for this application; nonunion at the arthrodesis site and failure of hardware occurred in 13% of arthrodeses. We no longer recommend this implant for this application.

Corona-vacuum failure mechanism test facilities

NASA Technical Reports Server (NTRS)

Lalli, V. R.; Mueller, L. A.; Koutnik, E. A.

1975-01-01

A nondestructive corona-vacuum test facility for testing high-voltage power system components has been developed using commercially available hardware. The facility simulates operating temperature and vacuum while monitoring coronal discharges with residual gases. Corona threshold voltages obtained from statorette tests with various gas-solid dielectric systems and comparison with calculated data support the following conclusions: (1) air gives the highest corona threshold voltage and helium the lowest, with argon and helium-xenon mixtures intermediate; (2) corona threshold voltage increases with gas pressure; (3) corona threshold voltage for an armature winding can be accurately calculated by using Paschen curves for a uniform field; and (4) Paschen curves for argon can be used to calculate the corona threshold voltage in He-Xe mixtures, for which Paschen curves are unavailable.-

Enhancements and Algorithms for Avionic Information Processing System Design Methodology.

DTIC Science & Technology

1982-06-16

programming algorithm is enhanced by incorporating task precedence constraints and hardware failures. Stochastic network methods are used to analyze...allocations in the presence of random fluctuations. Graph theoretic methods are used to analyze hardware designs, and new designs are constructed with...There, spatial dynamic programming (SDP) was used to solve a static, deterministic software allocation problem. Under the current contract the SDP

Immersion Cooling of Electronics in DoD Installations

DTIC Science & Technology

2016-05-01

2012). Bitcoin Mining Electronics Cooling Development In January 2013, inventor/consultant Mark Miyoshi began development of a two-phase cooling...system using Novec 649 to be used for cooling bitcoin mining hardware. After a short trial period, hardware power supply and logic-board failures...are reports of bitcoin mining companies vertically stacking two-phase immersion baths to improve the floor space density, but this approach is likely

Pratt and Whitney Overview and Advanced Health Management Program

NASA Technical Reports Server (NTRS)

Inabinett, Calvin

2008-01-01

Hardware Development Activity: Design and Test Custom Multi-layer Circuit Boards for use in the Fault Emulation Unit; Logic design performed using VHDL; Layout power system for lab hardware; Work lab issues with software developers and software testers; Interface with Engine Systems personnel with performance of Engine hardware components; Perform off nominal testing with new engine hardware.

Software for Managing Inventory of Flight Hardware

NASA Technical Reports Server (NTRS)

Salisbury, John; Savage, Scott; Thomas, Shirman

2003-01-01

The Flight Hardware Support Request System (FHSRS) is a computer program that relieves engineers at Marshall Space Flight Center (MSFC) of most of the non-engineering administrative burden of managing an inventory of flight hardware. The FHSRS can also be adapted to perform similar functions for other organizations. The FHSRS affords a combination of capabilities, including those formerly provided by three separate programs in purchasing, inventorying, and inspecting hardware. The FHSRS provides a Web-based interface with a server computer that supports a relational database of inventory; electronic routing of requests and approvals; and electronic documentation from initial request through implementation of quality criteria, acquisition, receipt, inspection, storage, and final issue of flight materials and components. The database lists both hardware acquired for current projects and residual hardware from previous projects. The increased visibility of residual flight components provided by the FHSRS has dramatically improved the re-utilization of materials in lieu of new procurements, resulting in a cost savings of over $1.7 million. The FHSRS includes subprograms for manipulating the data in the database, informing of the status of a request or an item of hardware, and searching the database on any physical or other technical characteristic of a component or material. The software structure forces normalization of the data to facilitate inquiries and searches for which users have entered mixed or inconsistent values.

Developing a CD-CBM Anticipatory Approach for Cavitation - Defining a Model-Based Descriptor Consistent Across Processes, Phase 1 Final Report Context-Dependent Prognostics and Health Assessment: A New Paradigm for Condition-based Maintenance SBIR Topic No. N98-114

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allgood, G.O.; Dress, W.B.; Kercel, S.W.

1999-06-01

The objective of this research, and subsequent testing, was to identify specific features of cavitation that could be used as a model-based descriptor in a context-dependent condition-based maintenance (CD-CBM) anticipatory prognostic and health assessment model. This descriptor is based on the physics of the phenomena, capturing the salient features of the process dynamics. The test methodology and approach were developed to make the cavitation features the dominant effect in the process and collected signatures. This would allow the accurate characterization of the salient cavitation features at different operational states. By developing such an abstraction, these attributes can be used asmore » a general diagnostic for a system or any of its components. In this study, the particular focus will be pumps. As many as 90% of pump failures are catastrophic. They seem to be operating normally and fail abruptly without warning. This is true whether the failure is sudden hardware damage requiring repair, such as a gasket failure, or a transition into an undesired operating mode, such as cavitation. This means that conventional diagnostic methods fail to predict 90% of incipient failures and that in addressing this problem, model-based methods can add value where it is actually needed.« less

Photogrammetric Deflection Measurements for the Tiltrotor Test Rig (TTR) Multi-Component Rotor Balance Calibration

NASA Technical Reports Server (NTRS)

Solis, Eduardo; Meyn, Larry

2016-01-01

Calibrating the internal, multi-component balance mounted in the Tiltrotor Test Rig (TTR) required photogrammetric measurements to determine the location and orientation of forces applied to the balance. The TTR, with the balance and calibration hardware attached, was mounted in a custom calibration stand. Calibration loads were applied using eleven hydraulic actuators, operating in tension only, that were attached to the forward frame of the calibration stand and the TTR calibration hardware via linkages with in-line load cells. Before the linkages were installed, photogrammetry was used to determine the location of the linkage attachment points on the forward frame and on the TTR calibration hardware. Photogrammetric measurements were used to determine the displacement of the linkage attachment points on the TTR due to deflection of the hardware under applied loads. These measurements represent the first photogrammetric deflection measurements to be made to support 6-component rotor balance calibration. This paper describes the design of the TTR and the calibration hardware, and presents the development, set-up and use of the photogrammetry system, along with some selected measurement results.

Long life assurance study for manned spacecraft long life hardware. Volume 1: Summary of long life assurance guidelines

NASA Technical Reports Server (NTRS)

1972-01-01

A long life assurance program for the development of design, process, test, and application guidelines for achieving reliable spacecraft hardware was conducted. The study approach consisted of a review of technical data performed concurrently with a survey of the aerospace industry. The data reviewed included design and operating characteristics, failure histories and solutions, and similar documents. The topics covered by the guidelines are reported. It is concluded that long life hardware is achieved through meticulous attention to many details and no simple set of rules can suffice.

Detection of Failure in Asynchronous Motor Using Soft Computing Method

NASA Astrophysics Data System (ADS)

Vinoth Kumar, K.; Sony, Kevin; Achenkunju John, Alan; Kuriakose, Anto; John, Ano P.

2018-04-01

This paper investigates the stator short winding failure of asynchronous motor also their effects on motor current spectrums. A fuzzy logic approach i.e., model based technique possibly will help to detect the asynchronous motor failure. Actually, fuzzy logic similar to humanoid intelligent methods besides expected linguistic empowering inferences through vague statistics. The dynamic model is technologically advanced for asynchronous motor by means of fuzzy logic classifier towards investigate the stator inter turn failure in addition open phase failure. A hardware implementation was carried out with LabVIEW for the online-monitoring of faults.

Evaluation of Cathode Air Flow Transients in a SOFC/GT Hybrid System Using Hardware in the Loop Simulation.

PubMed

Zhou, Nana; Yang, Chen; Tucker, David

2015-02-01

Thermal management in the fuel cell component of a direct fired solid oxide fuel cell gas turbine (SOFC/GT) hybrid power system can be improved by effective management and control of the cathode airflow. The disturbances of the cathode airflow were accomplished by diverting air around the fuel cell system through the manipulation of a hot-air bypass valve in open loop experiments, using a hardware-based simulation facility designed and built by the U.S. Department of Energy, National Energy Technology Laboratory (NETL). The dynamic responses of the fuel cell component and hardware component of the hybrid system were studied in this paper.

Quantifying effectiveness of failure prediction and response in HPC systems : methodology and example.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayo, Jackson R.; Chen, Frank Xiaoxiao; Pebay, Philippe Pierre

2010-06-01

Effective failure prediction and mitigation strategies in high-performance computing systems could provide huge gains in resilience of tightly coupled large-scale scientific codes. These gains would come from prediction-directed process migration and resource servicing, intelligent resource allocation, and checkpointing driven by failure predictors rather than at regular intervals based on nominal mean time to failure. Given probabilistic associations of outlier behavior in hardware-related metrics with eventual failure in hardware, system software, and/or applications, this paper explores approaches for quantifying the effects of prediction and mitigation strategies and demonstrates these using actual production system data. We describe context-relevant methodologies for determining themore » accuracy and cost-benefit of predictors. While many research studies have quantified the expected impact of growing system size, and the associated shortened mean time to failure (MTTF), on application performance in large-scale high-performance computing (HPC) platforms, there has been little if any work to quantify the possible gains from predicting system resource failures with significant but imperfect accuracy. This possibly stems from HPC system complexity and the fact that, to date, no one has established any good predictors of failure in these systems. Our work in the OVIS project aims to discover these predictors via a variety of data collection techniques and statistical analysis methods that yield probabilistic predictions. The question then is, 'How good or useful are these predictions?' We investigate methods for answering this question in a general setting, and illustrate them using a specific failure predictor discovered on a production system at Sandia.« less

EVA Training and Development Facilities

NASA Technical Reports Server (NTRS)

Cupples, Scott

2016-01-01

Overview: Vast majority of US EVA (ExtraVehicular Activity) training and EVA hardware development occurs at JSC; EVA training facilities used to develop and refine procedures and improve skills; EVA hardware development facilities test hardware to evaluate performance and certify requirement compliance; Environmental chambers enable testing of hardware from as large as suits to as small as individual components in thermal vacuum conditions.

Independent Orbiter Assessment (IOA): Assessment of the electrical power generation/fuel cell powerplant subsystem FMEA/CIL

NASA Technical Reports Server (NTRS)

Brown, K. L.; Bertsch, P. J.

1987-01-01

Results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Electrical Power Generation/Fuel Cell Powerplant (EPG/FCP) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline. A resolution of each discrepancy from the comparison was provided through additional analysis as required. This report documents the results of that comparison for the Orbiter EPG/FCP hardware.

Failure Analysis of Fractured Poppet from Space Shuttle Orbiter Flow Control Valve

NASA Technical Reports Server (NTRS)

Russell, Richard

2010-01-01

This slide presentation reviews the failure analysis of a fractured poppet from a flow control valve (FCV) used on the space shuttle. This presentation has focused on the laboratory analysis of the failed hardware. The use of Scanning electron fractography during the investigation led to the conclusion that the poppet failed due to fatigue cracking that, most likely, occurred under changing loading conditions. The initial investigation led to a more thorough test of poppets that had been retired, this testing led to the conclusion that the thumbnail cracks in the flight hardware had existed for the life of the shuttle program. This led to a program to develop an eddy current technique that was capable of detecting small very tight cracks.

Water system hardware and management rehabilitation: Qualitative evidence from Ghana, Kenya, and Zambia.

PubMed

Klug, Tori; Shields, Katherine F; Cronk, Ryan; Kelly, Emma; Behnke, Nikki; Lee, Kristen; Bartram, Jamie

2017-05-01

Sufficient, safe, continuously available drinking water is important for human health and development, yet one in three handpumps in sub-Saharan Africa are non-functional at any given time. Community management, coupled with access to external technical expertise and spare parts, is a widely promoted model for rural water supply management. However, there is limited evidence describing how community management can address common hardware and management failures of rural water systems in sub-Saharan Africa. We identified hardware and management rehabilitation pathways using qualitative data from 267 interviews and 57 focus group discussions in Ghana, Kenya, and Zambia. Study participants were water committee members, community members, and local leaders in 18 communities (six in each study country) with water systems managed by a water committee and supported by World Vision (WV), an international non-governmental organization (NGO). Government, WV or private sector employees engaged in supporting the water systems were also interviewed. Inductive analysis was used to allow for pathways to emerge from the data, based on the perspectives and experiences of study participants. Four hardware rehabilitation pathways were identified, based on the types of support used in rehabilitation. Types of support were differentiated as community or external. External support includes financial and/or technical support from government or WV employees. Community actor understanding of who to contact when a hardware breakdown occurs and easy access to technical experts were consistent reasons for rapid rehabilitation for all hardware rehabilitation pathways. Three management rehabilitation pathways were identified. All require the involvement of community leaders and were best carried out when the action was participatory. The rehabilitation pathways show how available resources can be leveraged to restore hardware breakdowns and management failures for rural water systems in sub-Saharan Africa. Governments, NGOs, and private sector actors can better build capacity of community actors by focusing on their role in rehabilitating hardware and management and to ensure that they are able to quickly contact external support actors when needed for rehabilitation. Using qualitative and participatory methods allows for insight into rapid rehabilitation of hardware and management. Copyright © 2017 Elsevier GmbH. All rights reserved.

First incremental buy for Increment 2 of the Space Transportation System (STS)

NASA Technical Reports Server (NTRS)

1989-01-01

Thiokol manufactured and delivered 9 flight motors to KSC on schedule. All test flights were successful. All spent SRMs were recovered. Design, development, manufacture, and delivery of required transportation, handling, and checkout equipment to MSFC and to KSC were completed on schedule. All items of data required by DPD 400 were prepared and delivered as directed. In the system requirements and analysis area, the point of departure from Buy 1 to the operational phase was developed in significant detail with a complete set of transition documentation available. The documentation prepared during the Buy 1 program was maintained and updated where required. The following flight support activities should be continued through other production programs: as-built materials usage tracking on all flight hardware; mass properties reporting for all flight hardware until sample size is large enough to verify that the weight limit requirements were met; ballistic predictions and postflight performance assessments for all production flights; and recovered SRM hardware inspection and anomaly identification. In the safety, reliability, and quality assurance area, activities accomplished were assurance oriented in nature and specifically formulated to prevent problems and hardware failures. The flight program to date has adequately demonstrated the success of this assurance approach. The attention focused on details of design, analysis, manufacture, and inspection to assure the production of high-quality hardware has resulted in the absence of flight failures. The few anomalies which did occur were evaluated, design or manufacturing changes incorporated, and corrective actions taken to preclude recurrence.

The implementation and use of Ada on distributed systems with high reliability requirements

NASA Technical Reports Server (NTRS)

Knight, J. C.; Gregory, S. T.; Urquhart, J. I. A.

1984-01-01

The use and implementation of Ada (a trade mark of the US Dept. of Defense) in distributed environments in which the hardware are assumed to be unreliable were investigated. The possibility that a distributed system is programmed entirely in Ada so that the individual tasks of the system are unconcerned with which processors they are executing on and failures occurring in the underlying hardware were examined.

ALS rocket engine combustion devices design and demonstration

NASA Technical Reports Server (NTRS)

Arreguin, Steve

1989-01-01

Work performed during Phase one is summarized and the significant technical and programmatic accomplishments occurring during this period are documented. Besides a summary of the results, methodologies, trade studies, design, fabrication, and hardware conditions; the following are included: the evolving Maintainability Plan, Reliability Program Plan, Failure Summary and Analysis Report, and the Failure Mode and Effect Analysis.

The (human) science of medical virtual learning environments

PubMed Central

Stone, Robert J.

2011-01-01

The uptake of virtual simulation technologies in both military and civilian surgical contexts has been both slow and patchy. The failure of the virtual reality community in the 1990s and early 2000s to deliver affordable and accessible training systems stems not only from an obsessive quest to develop the ‘ultimate’ in so-called ‘immersive’ hardware solutions, from head-mounted displays to large-scale projection theatres, but also from a comprehensive lack of attention to the needs of the end users. While many still perceive the science of simulation to be defined by technological advances, such as computing power, specialized graphics hardware, advanced interactive controllers, displays and so on, the true science underpinning simulation—the science that helps to guarantee the transfer of skills from the simulated to the real—is that of human factors, a well-established discipline that focuses on the abilities and limitations of the end user when designing interactive systems, as opposed to the more commercially explicit components of technology. Based on three surgical simulation case studies, the importance of a human factors approach to the design of appropriate simulation content and interactive hardware for medical simulation is illustrated. The studies demonstrate that it is unnecessary to pursue real-world fidelity in all instances in order to achieve psychological fidelity—the degree to which the simulated tasks reproduce and foster knowledge, skills and behaviours that can be reliably transferred to real-world training applications. PMID:21149363

NASA Contractor Report: Guidelines for Proof Test Analysis

NASA Technical Reports Server (NTRS)

Chell, G. G.; McClung, R. C.; Kuhlman, C. J.; Russell, D. A.; Garr, K.; Donnelly, B.

1997-01-01

These Guidelines integrate state-of-the-art Elastic-Plastic Fracture Mechanics (EPFM) and proof test implementation issues into a comprehensive proof test analysis procedure in the form of a Road Map which identifies the types of data, fracture mechanics based parameters, and calculations needed to perform flaw screening and minimum proof load analyses of fracture critical components. Worked examples are presented to illustrate the application of the Road Map to proof test analysis. The state-of-the-art fracture technology employed in these Guidelines is based on the EPFM parameter, J, and a pictorial representation of a J fracture analysis, called the Failure Assessment Diagram (FAD) approach. The recommended fracture technology is validated using finite element J results, and laboratory and hardware fracture test results on the nickel-based superalloy IN-718, the aluminum alloy 2024-T351 1, and ferritic pressure vessel steels. In all cases the laboratory specimens and hardware failed by ductile mechanisms. Advanced proof test analyses involving probability analysis and Multiple Cycle Proof Testing (MCPT) are addressed. Finally, recommendations are provided on to how to account for the effects of the proof test overload on subsequent service fatigue and fracture behaviors.

The Influence of Various Factors on High School Football Helmet Face Mask Removal: A Retrospective, Cross-Sectional Analysis

PubMed Central

Swartz, Erik E; Decoster, Laura C; Norkus, Susan A; Cappaert, Thomas A

2007-01-01

Context: Most research on face mask removal has been performed on unused equipment. Objective: To identify and compare factors that influence the condition of helmet components and their relationship to face mask removal. Design: A cross-sectional, retrospective study. Setting: Five athletic equipment reconditioning/recertification facilities. Participants: 2584 helmets from 46 high school football teams representing 5 geographic regions. Intervention(s): Helmet characteristics (brand, model, hardware components) were recorded. Helmets were mounted and face mask removal was attempted using a cordless screwdriver. The 2004 season profiles and weather histories were obtained for each high school. Main Outcome Measure(s): Success and failure (including reason) for removal of 4 screws from the face mask were noted. Failure rates among regions, teams, reconditioning year, and screw color (type) were compared. Weather histories were compared. We conducted a discriminant analysis to determine if weather variables, region, helmet brand and model, reconditioning year, and screw color could predict successful face mask removal. Metallurgic analysis of screw samples was performed. Results: All screws were successfully removed from 2165 (84%) helmets. At least 1 screw could not be removed from 419 (16%) helmets. Significant differences were found for mean screw failure per helmet among the 5 regions, with the Midwest having the lowest failure rate (0.08 ± 0.38) and the Southern (0.33 ± 0.72), the highest. Differences were found in screw failure rates among the 46 teams (F1,45 = 9.4, P < .01). Helmets with the longest interval since last reconditioning (3 years) had the highest failure rate, 0.47 ± 0.93. Differences in success rates were found among 4 screw types (χ21,4 = 647, P < .01), with silver screws having the lowest percentage of failures (3.4%). A discriminant analysis (Λ = .932, χ214,n=2584 = 175.34, P < .001) revealed screw type to be the strongest predictor of successful removal. Conclusions: Helmets with stainless steel or nickel-plated carbon steel screws reconditioned in the previous year had the most favorable combination of factors for successful screw removal. T-nut spinning at the side screw locations was the most common reason and location for failure. PMID:17597938

Analysis, Design, and Prototyping Of Accounting Software for Navy Signal Intelligence Collection Systems Return On Investment Reporting

DTIC Science & Technology

2010-09-01

The MasterNet project continued to expand in software and hardware complexity until its failure ( Szilagyi , n.d.). Despite all of the issues...were used for MasterNet ( Szilagyi , n.d.). Although executive management committed significant financial resources to MasterNet, Bank of America...implementation failure as well as project- management failure as a whole ( Szilagyi , n.d.). The lesson learned from this vignette is the importance of setting

ISS Ammonia Pump Failure, Recovery, and Lesson Learned A Hydrodynamic Bearing Perspective

NASA Technical Reports Server (NTRS)

Bruckner, Robert J.; Manco, Richard A., II

2014-01-01

The design, development, and operation of long duration spaceflight hardware has become an evolutionary process in which meticulous attention to details and lessons learned from previous experiences play a critical role. Invaluable to this process is the ability to retrieve and examine spaceflight hardware that has experienced a premature failure. While these situations are rare and unfortunate, the failure investigation and recovery from the event serve a valuable purpose in advancing future space mechanism development. Such a scenario began on July 31, 2010 with the premature failure of an ammonia pump on the external active thermal control system of the International Space Station. The ground-based inspections of the returned pump and ensuing failure investigation revealed five potential bearing forces that were un-accounted for in the design phase and qualification testing of the pump. These forces could combine in a number of random orientations to overload the pump bearings leading to solid-surface contact, wear, and premature failure. The recovery plan identified one of these five forces as being related to the square of the operating speed of the pump and this fact was used to recover design life through a change in flight rules for the operation of the pump module. Through the course of the failure investigation, recovery, and follow-on assessment of pump wear life, design guidance has been developed to improve the life of future mechanically pumped thermal control systems for both human and robotic exploration missions.

Twiddler's syndrome in spinal cord stimulation.

PubMed

Al-Mahfoudh, Rafid; Chan, Yuen; Chong, Hsu Pheen; Farah, Jibril Osman

2016-01-01

The aims are to present a case series of Twiddler's syndrome in spinal cord stimulators with analysis of the possible mechanism of this syndrome and discuss how this phenomenon can be prevented. Data were collected retrospectively between 2007 and 2013 for all patients presenting with failure of spinal cord stimulators. The diagnostic criterion for Twiddler's syndrome is radiological evidence of twisting of wires in the presence of failure of spinal cord stimulation. Our unit implants on average 110 spinal cord stimulators a year. Over the 5-year study period, all consecutive cases of spinal cord stimulation failure were studied. Three patients with Twiddler's syndrome were identified. Presentation ranged from 4 to 228 weeks after implantation. Imaging revealed repeated rotations and twisting of the wires of the spinal cord stimulators leading to hardware failure. To the best of our knowledge this is the first reported series of Twiddler's syndrome with implantable pulse generators (IPGs) for spinal cord stimulation. Hardware failure is not uncommon in spinal cord stimulation. Awareness and identification of Twiddler's syndrome may help prevent its occurrence and further revisions. This may be achieved by implanting the IPG in the lumbar region subcutaneously above the belt line. Psychological intervention may have a preventative role for those who are deemed at high risk of Twiddler's syndrome from initial psychological screening.

Independent Orbiter Assessment (IOA): Assessment of the remote manipulator system FMEA/CIL

NASA Technical Reports Server (NTRS)

Tangorra, F.; Grasmeder, R. F.; Montgomery, A. D.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Remote Manipulator System (RMS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were than compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. The results of that comparison for the Orbiter RMS hardware are documented. The IOA product for the RMS analysis consisted of 604 failure mode worksheets that resulted in 458 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 45 FMEAs and 321 CIL items. This comparison produced agreement on all but 154 FMEAs which caused differences in 137 CIL items.

Independent Orbiter Assessment (IOA): Assessment of the hydraulics/water spray boiler subsystem

NASA Technical Reports Server (NTRS)

Bynum, M. C.; Duval, J. D.; Parkman, W. E.; Davidson, W. R.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Hydraulics/Water Spray Boiler (HYD/WSB) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter HYD/WSB hardware. The IOA product for the HYD/WSB analysis consisted of 447 failure mode worksheets that resulted in 183 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 364 FMEAs and 111 CIL items. This comparison produced agreement on all but 68 FMEAs which caused differences in 23 CIL items.

Independent Orbiter Assessment (IOA): Assessment of the Electrical Power Distribution and Control/Electrical Power Generation (EPD and C/EPG) FMEA/CIL

NASA Technical Reports Server (NTRS)

Mccants, C. N.; Bearrow, M.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Electrical Power Distribution and Control/Electrical Power Generation (EPD and C/EPG) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison was provided through additional analysis as required. The results of that comparison is documented for the Orbiter EPD and C/EPG hardware. The IOA product for the EPD and C/EPG analysis consisted of 263 failure mode worksheets that resulted in 42 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 211 FMEA and 47 CIL items.

Independent Orbiter Assessment (IOA): Assessment of the guidance, navigation, and control subsystem FMEA/CIL

NASA Technical Reports Server (NTRS)

Trahan, W. H.; Odonnell, R. A.; Pietz, K. C.; Drapela, L. J.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Guidance, Navigation, and Control System (GNC) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. The results of that comparison for the Orbiter GNC hardware is documented. The IOA product for the GNC analysis consisted of 141 failure mode worksheets that resulted in 24 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 148 FMEAs and 36 CIL items. This comparison produced agreement on all but 56 FMEAs which caused differences in zero CIL items.

A.I.-based real-time support for high performance aircraft operations

NASA Technical Reports Server (NTRS)

Vidal, J. J.

1985-01-01

Artificial intelligence (AI) based software and hardware concepts are applied to the handling system malfunctions during flight tests. A representation of malfunction procedure logic using Boolean normal forms are presented. The representation facilitates the automation of malfunction procedures and provides easy testing for the embedded rules. It also forms a potential basis for a parallel implementation in logic hardware. The extraction of logic control rules, from dynamic simulation and their adaptive revision after partial failure are examined. It uses a simplified 2-dimensional aircraft model with a controller that adaptively extracts control rules for directional thrust that satisfies a navigational goal without exceeding pre-established position and velocity limits. Failure recovery (rule adjusting) is examined after partial actuator failure. While this experiment was performed with primitive aircraft and mission models, it illustrates an important paradigm and provided complexity extrapolations for the proposed extraction of expertise from simulation, as discussed. The use of relaxation and inexact reasoning in expert systems was also investigated.

Independent Orbiter Assessment (IOA): Assessment of the body flap subsystem FMEA/CIL

NASA Technical Reports Server (NTRS)

Wilson, R. E.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Body Flap (BF) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter BF hardware. The IOA product for the BF analysis consisted of 43 failure mode worksheets that resulted in 19 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 34 FMEAs and 15 CIL items. This comparison produced agreement on all CIL items. Based on the Pre 51-L baseline, all non-CIL FMEAs were also in agreement.

Independent Orbiter Assessment (IOA): Assessment of the elevon actuator subsystem FMEA/CIL

NASA Technical Reports Server (NTRS)

Wilson, R. E.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Elevon Subsystem hardware, generating draft failure modes, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter Elevon hardware. The IOA product for the Elevon analysis consisted of 25 failure mode worksheets that resulted in 17 potential critical items being identified. Comparison was made to the NASA FMEA/CIL, which consisted of 23 FMEAs and 13 CIL items. This comparison produced agreement on all CIL items. Based on the Pre 51-L baseline, all non-CIL FMEAs were also in agreement.

Independent Orbiter Assessment (IOA): Assessment of instrumental subsystem FMEA/CIL

NASA Technical Reports Server (NTRS)

Gardner, J. R.; Addis, A. W.

1988-01-01

The McDonnell Douglas Astronautics Company (MDAC) was selected in June 1986 to perform an Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL). The IOA effort first completed an analysis of the Instrumentation hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline. A resolution of each discrepancy from the comparison is provided through additional analysis as required. The results of that comparison for the Orbiter Instrumentation hardware are documented. The IOA product for Instrumentation analysis consisted of 107 failure mode worksheets that resulted in 22 critical items being identified. Comparison was made to the Pre 51-L NASA baseline with 14 Post 51-L FMEAs added, which consists of 96 FMEAs and 18 CIL items. This comparison produced agreement on all but 25 FMEAs which caused differences in 5 CIL items.

Compiler-Assisted Multiple Instruction Rollback Recovery Using a Read Buffer. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Alewine, Neal Jon

1993-01-01

Multiple instruction rollback (MIR) is a technique to provide rapid recovery from transient processor failures and was implemented in hardware by researchers and slow in mainframe computers. Hardware-based MIR designs eliminate rollback data hazards by providing data redundancy implemented in hardware. Compiler-based MIR designs were also developed which remove rollback data hazards directly with data flow manipulations, thus eliminating the need for most data redundancy hardware. Compiler-assisted techniques to achieve multiple instruction rollback recovery are addressed. It is observed that data some hazards resulting from instruction rollback can be resolved more efficiently by providing hardware redundancy while others are resolved more efficiently with compiler transformations. A compiler-assisted multiple instruction rollback scheme is developed which combines hardware-implemented data redundancy with compiler-driven hazard removal transformations. Experimental performance evaluations were conducted which indicate improved efficiency over previous hardware-based and compiler-based schemes. Various enhancements to the compiler transformations and to the data redundancy hardware developed for the compiler-assisted MIR scheme are described and evaluated. The final topic deals with the application of compiler-assisted MIR techniques to aid in exception repair and branch repair in a speculative execution architecture.

Open-source hardware for medical devices

PubMed Central

2016-01-01

Open-source hardware is hardware whose design is made publicly available so anyone can study, modify, distribute, make and sell the design or the hardware based on that design. Some open-source hardware projects can potentially be used as active medical devices. The open-source approach offers a unique combination of advantages, including reducing costs and faster innovation. This article compares 10 of open-source healthcare projects in terms of how easy it is to obtain the required components and build the device. PMID:27158528

Open-source hardware for medical devices.

PubMed

Niezen, Gerrit; Eslambolchilar, Parisa; Thimbleby, Harold

2016-04-01

Open-source hardware is hardware whose design is made publicly available so anyone can study, modify, distribute, make and sell the design or the hardware based on that design. Some open-source hardware projects can potentially be used as active medical devices. The open-source approach offers a unique combination of advantages, including reducing costs and faster innovation. This article compares 10 of open-source healthcare projects in terms of how easy it is to obtain the required components and build the device.

Reliability of Beam Loss Monitors System for the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Guaglio, G.; Dehning, B.; Santoni, C.

2004-11-01

The employment of superconducting magnets in high energy colliders opens challenging failure scenarios and brings new criticalities for the whole system protection. For the LHC beam loss protection system, the failure rate and the availability requirements have been evaluated using the Safety Integrity Level (SIL) approach. A downtime cost evaluation is used as input for the SIL approach. The most critical systems, which contribute to the final SIL value, are the dump system, the interlock system, the beam loss monitors system and the energy monitor system. The Beam Loss Monitors System (BLMS) is critical for short and intense particle losses, while at medium and higher loss time it is assisted by other systems, such as the quench protection system and the cryogenic system. For BLMS, hardware and software have been evaluated in detail. The reliability input figures have been collected using historical data from the SPS, using temperature and radiation damage experimental data as well as using standard databases. All the data have been processed by reliability software (Isograph). The analysis ranges from the components data to the system configuration.

U.S. Reliance on Foreign IT: Mitigating Risks Associated with Foreign Sources of Hardware Components, Summer 2008 - Project 08-03

DTIC Science & Technology

2008-08-01

REPORT MAY 2008 - AUGUST 2008 U.S. Reliance on Foreign IT: Mitigating Risks Associated with Foreign Sources of Hardware Components N/A N/A N/A 08...Clinger-Cohen Act CIA Central Intelligence Agency CIO Chief Information Officer CMOS Complimentary Metal -Oxide Semiconductor DARPA Defense Advanced

Compiler-assisted multiple instruction rollback recovery using a read buffer

NASA Technical Reports Server (NTRS)

Alewine, N. J.; Chen, S.-K.; Fuchs, W. K.; Hwu, W.-M.

1993-01-01

Multiple instruction rollback (MIR) is a technique that has been implemented in mainframe computers to provide rapid recovery from transient processor failures. Hardware-based MIR designs eliminate rollback data hazards by providing data redundancy implemented in hardware. Compiler-based MIR designs have also been developed which remove rollback data hazards directly with data-flow transformations. This paper focuses on compiler-assisted techniques to achieve multiple instruction rollback recovery. We observe that some data hazards resulting from instruction rollback can be resolved efficiently by providing an operand read buffer while others are resolved more efficiently with compiler transformations. A compiler-assisted multiple instruction rollback scheme is developed which combines hardware-implemented data redundancy with compiler-driven hazard removal transformations. Experimental performance evaluations indicate improved efficiency over previous hardware-based and compiler-based schemes.

Failure Engineering Study and Accelerated Stress Test Results for the Mars Global Surveyor Spacecraft's Power Shunt Assemblies

NASA Technical Reports Server (NTRS)

Gibbel, Mark; Larson, Timothy

2000-01-01

An Engineering-of-Failure approach to designing and executing an accelerated product qualification test was performed to support a risk assessment of a "work-around" necessitated by an on-orbit failure of another piece of hardware on the Mars Global Surveyor spacecraft. The proposed work-around involved exceeding the previous qualification experience both in terms of extreme cold exposure level and in terms of demonstrated low cycle fatigue life for the power shunt assemblies. An analysis was performed to identify potential failure sites, modes and associated failure mechanisms consistent with the new use conditions. A test was then designed and executed which accelerated the failure mechanisms identified by analysis. Verification of the resulting failure mechanism concluded the effort.

NASA-STD-(I)-6016, Standard Materials and Processes Requirements for Spacecraft

NASA Technical Reports Server (NTRS)

Pedley, Michael; Griffin, Dennis

2006-01-01

This document is directed toward Materials and Processes (M&P) used in the design, fabrication, and testing of flight components for all NASA manned, unmanned, robotic, launch vehicle, lander, in-space and surface systems, and spacecraft program/project hardware elements. All flight hardware is covered by the M&P requirements of this document, including vendor designed, off-the-shelf, and vendor furnished items. Materials and processes used in interfacing ground support equipment (GSE); test equipment; hardware processing equipment; hardware packaging; and hardware shipment shall be controlled to prevent damage to or contamination of flight hardware.

Reliability training

NASA Technical Reports Server (NTRS)

Lalli, Vincent R. (Editor); Malec, Henry A. (Editor); Dillard, Richard B.; Wong, Kam L.; Barber, Frank J.; Barina, Frank J.

1992-01-01

Discussed here is failure physics, the study of how products, hardware, software, and systems fail and what can be done about it. The intent is to impart useful information, to extend the limits of production capability, and to assist in achieving low cost reliable products. A review of reliability for the years 1940 to 2000 is given. Next, a review of mathematics is given as well as a description of what elements contribute to product failures. Basic reliability theory and the disciplines that allow us to control and eliminate failures are elucidated.

A reminder on millisecond timing accuracy and potential replication failure in computer-based psychology experiments: An open letter.

PubMed

Plant, Richard R

2016-03-01

There is an ongoing 'replication crisis' across the field of psychology in which researchers, funders, and members of the public are questioning the results of some scientific studies and the validity of the data they are based upon. However, few have considered that a growing proportion of research in modern psychology is conducted using a computer. Could it simply be that the hardware and software, or experiment generator, being used to run the experiment itself be a cause of millisecond timing error and subsequent replication failure? This article serves as a reminder that millisecond timing accuracy in psychology studies remains an important issue and that care needs to be taken to ensure that studies can be replicated on current computer hardware and software.

Independent Orbiter Assessment (IOA): Assessment of the Electrical Power Distribution and Control Subsystem, Volume 2

NASA Technical Reports Server (NTRS)

Schmeckpeper, K. R.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA first completed an analysis of the Electrical Power Distribution and Control (EPD and C) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter EPD and C hardware. Volume 2 continues the presentation of IOA worksheets.

Extravehicular Mobility Unit (EMU) / International Space Station (ISS) Coolant Loop Failure and Recovery

NASA Technical Reports Server (NTRS)

Lewis, John F.; Cole, Harold; Cronin, Gary; Gazda, Daniel B.; Steele, John

2006-01-01

Following the Colombia accident, the Extravehicular Mobility Units (EMU) onboard ISS were unused for several months. Upon startup, the units experienced a failure in the coolant system. This failure resulted in the loss of Extravehicular Activity (EVA) capability from the US segment of ISS. With limited on-orbit evidence, a team of chemists, engineers, metallurgists, and microbiologists were able to identify the cause of the failure and develop recovery hardware and procedures. As a result of this work, the ISS crew regained the capability to perform EVAs from the US segment of the ISS.

40 CFR 68.67 - Process hazard analysis.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) CHEMICAL ACCIDENT PREVENTION PROVISIONS Program 3 Prevention Program § 68.67 Process hazard analysis. (a... instrumentation with alarms, and detection hardware such as hydrocarbon sensors.); (4) Consequences of failure of...

40 CFR 68.67 - Process hazard analysis.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) CHEMICAL ACCIDENT PREVENTION PROVISIONS Program 3 Prevention Program § 68.67 Process hazard analysis. (a... instrumentation with alarms, and detection hardware such as hydrocarbon sensors.); (4) Consequences of failure of...

A Comprehensive Reliability Methodology for Assessing Risk of Reusing Failed Hardware Without Corrective Actions with and Without Redundancy

NASA Technical Reports Server (NTRS)

Putcha, Chandra S.; Mikula, D. F. Kip; Dueease, Robert A.; Dang, Lan; Peercy, Robert L.

1997-01-01

This paper deals with the development of a reliability methodology to assess the consequences of using hardware, without failure analysis or corrective action, that has previously demonstrated that it did not perform per specification. The subject of this paper arose from the need to provide a detailed probabilistic analysis to calculate the change in probability of failures with respect to the base or non-failed hardware. The methodology used for the analysis is primarily based on principles of Monte Carlo simulation. The random variables in the analysis are: Maximum Time of Operation (MTO) and operation Time of each Unit (OTU) The failure of a unit is considered to happen if (OTU) is less than MTO for the Normal Operational Period (NOP) in which this unit is used. NOP as a whole uses a total of 4 units. Two cases are considered. in the first specialized scenario, the failure of any operation or system failure is considered to happen if any of the units used during the NOP fail. in the second specialized scenario, the failure of any operation or system failure is considered to happen only if any two of the units used during the MOP fail together. The probability of failure of the units and the system as a whole is determined for 3 kinds of systems - Perfect System, Imperfect System 1 and Imperfect System 2. in a Perfect System, the operation time of the failed unit is the same as that of the MTO. In an Imperfect System 1, the operation time of the failed unit is assumed as 1 percent of the MTO. In an Imperfect System 2, the operation time of the failed unit is assumed as zero. in addition, simulated operation time of failed units is assumed as 10 percent of the corresponding units before zero value. Monte Carlo simulation analysis is used for this study. Necessary software has been developed as part of this study to perform the reliability calculations. The results of the analysis showed that the predicted change in failure probability (P(sub F)) for the previously failed units is as high as 49 percent above the baseline (perfect system) for the worst case. The predicted change in system P(sub F) for the previously failed units is as high as 36% for single unit failure without any redundancy. For redundant systems, with dual unit failure, the predicted change in P(sub F) for the previously failed units is as high as 16%. These results will help management to make decisions regarding the consequences of using previously failed units without adequate failure analysis or corrective action.

JAVA Stereo Display Toolkit

NASA Technical Reports Server (NTRS)

Edmonds, Karina

2008-01-01

This toolkit provides a common interface for displaying graphical user interface (GUI) components in stereo using either specialized stereo display hardware (e.g., liquid crystal shutter or polarized glasses) or anaglyph display (red/blue glasses) on standard workstation displays. An application using this toolkit will work without modification in either environment, allowing stereo software to reach a wider audience without sacrificing high-quality display on dedicated hardware. The toolkit is written in Java for use with the Swing GUI Toolkit and has cross-platform compatibility. It hooks into the graphics system, allowing any standard Swing component to be displayed in stereo. It uses the OpenGL graphics library to control the stereo hardware and to perform the rendering. It also supports anaglyph and special stereo hardware using the same API (application-program interface), and has the ability to simulate color stereo in anaglyph mode by combining the red band of the left image with the green/blue bands of the right image. This is a low-level toolkit that accomplishes simply the display of components (including the JadeDisplay image display component). It does not include higher-level functions such as disparity adjustment, 3D cursor, or overlays all of which can be built using this toolkit.

Design and evaluation of a fault-tolerant multiprocessor using hardware recovery blocks

NASA Technical Reports Server (NTRS)

Lee, Y. H.; Shin, K. G.

1982-01-01

A fault-tolerant multiprocessor with a rollback recovery mechanism is discussed. The rollback mechanism is based on the hardware recovery block which is a hardware equivalent to the software recovery block. The hardware recovery block is constructed by consecutive state-save operations and several state-save units in every processor and memory module. When a fault is detected, the multiprocessor reconfigures itself to replace the faulty component and then the process originally assigned to the faulty component retreats to one of the previously saved states in order to resume fault-free execution. A mathematical model is proposed to calculate both the coverage of multi-step rollback recovery and the risk of restart. A performance evaluation in terms of task execution time is also presented.

One Size Does Not Fit All: Human Failure Event Decomposition and Task Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronald Laurids Boring, PhD

2014-09-01

In the probabilistic safety assessments (PSAs) used in the nuclear industry, human failure events (HFEs) are determined as a subset of hardware failures, namely those hardware failures that could be triggered or exacerbated by human action or inaction. This approach is top-down, starting with hardware faults and deducing human contributions to those faults. Elsewhere, more traditionally human factors driven approaches would tend to look at opportunities for human errors first in a task analysis and then identify which of those errors is risk significant. The intersection of top-down and bottom-up approaches to defining HFEs has not been carefully studied. Ideally,more » both approaches should arrive at the same set of HFEs. This question remains central as human reliability analysis (HRA) methods are generalized to new domains like oil and gas. The HFEs used in nuclear PSAs tend to be top-down—defined as a subset of the PSA—whereas the HFEs used in petroleum quantitative risk assessments (QRAs) are more likely to be bottom-up—derived from a task analysis conducted by human factors experts. The marriage of these approaches is necessary in order to ensure that HRA methods developed for top-down HFEs are also sufficient for bottom-up applications. In this paper, I first review top-down and bottom-up approaches for defining HFEs and then present a seven-step guideline to ensure a task analysis completed as part of human error identification decomposes to a level suitable for use as HFEs. This guideline illustrates an effective way to bridge the bottom-up approach with top-down requirements.« less

Tethered Satellite System Contingency Investigation Board

NASA Technical Reports Server (NTRS)

1992-01-01

The Tethered Satellite System (TSS-1) was launched aboard the Space Shuttle Atlantis (STS-46) on July 31, 1992. During the attempted on-orbit operations, the Tethered Satellite System failed to deploy successfully beyond 256 meters. The satellite was retrieved successfully and was returned on August 6, 1992. The National Aeronautics and Space Administration (NASA) Associate Administrator for Space Flight formed the Tethered Satellite System (TSS-1) Contingency Investigation Board on August 12, 1992. The TSS-1 Contingency Investigation Board was asked to review the anomalies which occurred, to determine the probable cause, and to recommend corrective measures to prevent recurrence. The board was supported by the TSS Systems Working group as identified in MSFC-TSS-11-90, 'Tethered Satellite System (TSS) Contingency Plan'. The board identified five anomalies for investigation: initial failure to retract the U2 umbilical; initial failure to flyaway; unplanned tether deployment stop at 179 meters; unplanned tether deployment stop at 256 meters; and failure to move tether in either direction at 224 meters. Initial observations of the returned flight hardware revealed evidence of mechanical interference by a bolt with the level wind mechanism travel as well as a helical shaped wrap of tether which indicated that the tether had been unwound from the reel beyond the travel by the level wind mechanism. Examination of the detailed mission events from flight data and mission logs related to the initial failure to flyaway and the failure to move in either direction at 224 meters, together with known preflight concerns regarding slack tether, focused the assessment of these anomalies on the upper tether control mechanism. After the second meeting, the board requested the working group to complete and validate a detailed integrated mission sequence to focus the fault tree analysis on a stuck U2 umbilical, level wind mechanical interference, and slack tether in upper tether control mechanism and to prepare a detailed plan for hardware inspection, test, and analysis including any appropriate hardware disassembly.

Tethered Satellite System Contingency Investigation Board

NASA Astrophysics Data System (ADS)

1992-11-01

The Tethered Satellite System (TSS-1) was launched aboard the Space Shuttle Atlantis (STS-46) on July 31, 1992. During the attempted on-orbit operations, the Tethered Satellite System failed to deploy successfully beyond 256 meters. The satellite was retrieved successfully and was returned on August 6, 1992. The National Aeronautics and Space Administration (NASA) Associate Administrator for Space Flight formed the Tethered Satellite System (TSS-1) Contingency Investigation Board on August 12, 1992. The TSS-1 Contingency Investigation Board was asked to review the anomalies which occurred, to determine the probable cause, and to recommend corrective measures to prevent recurrence. The board was supported by the TSS Systems Working group as identified in MSFC-TSS-11-90, 'Tethered Satellite System (TSS) Contingency Plan'. The board identified five anomalies for investigation: initial failure to retract the U2 umbilical; initial failure to flyaway; unplanned tether deployment stop at 179 meters; unplanned tether deployment stop at 256 meters; and failure to move tether in either direction at 224 meters. Initial observations of the returned flight hardware revealed evidence of mechanical interference by a bolt with the level wind mechanism travel as well as a helical shaped wrap of tether which indicated that the tether had been unwound from the reel beyond the travel by the level wind mechanism. Examination of the detailed mission events from flight data and mission logs related to the initial failure to flyaway and the failure to move in either direction at 224 meters, together with known preflight concerns regarding slack tether, focused the assessment of these anomalies on the upper tether control mechanism. After the second meeting, the board requested the working group to complete and validate a detailed integrated mission sequence to focus the fault tree analysis on a stuck U2 umbilical, level wind mechanical interference, and slack tether in upper tether control mechanism and to prepare a detailed plan for hardware inspection, test, and analysis including any appropriate hardware disassembly.

ATS-6 engineering performance report. Volume 6: Scientific experiments

NASA Technical Reports Server (NTRS)

Wales, R. O. (Editor)

1981-01-01

Evaluations include a very high resolution radiometer, a radio beacon experiment, environmental measurement experiments (EME), EME support hardware, EME anomalies and failures, EME results, and US/USSR magnetometer experiments.

Complications of short versus long cephalomedullary nail for intertrochanteric femur fractures, minimum 1 year follow-up.

PubMed

Vaughn, Josh; Cohen, Eric; Vopat, Bryan G; Kane, Patrick; Abbood, Emily; Born, Christopher

2015-05-01

Hip fractures are becoming increasingly common resulting in significant morbidity, mortality and raising healthcare costs. Both short and long cephalomedullary devices are currently employed to treat intertrochanteric hip fractures. However, which device is optimal continues to be debated as each implant has unique characteristics and theoretical advantages. This study looked to identify rates of complications associated with both long and short cephalomedullary nails for the treatment of intertrochanteric hip fractures. We retrospectively reviewed charts from 2006 to 2011, and we identified 256 patients were identified with AO class 31.1-32.3 fractures. Sixty were treated with short nails and 196 with long nails. Radiographs and charts were then analysed for failures and hardware complications. Catastrophic failure and hardware complication rates were not statistically different between short or long cephalomedullary nails. The overall catastrophic failure rate was 3.1 %; there was a 5 % failure rate in the short-nail group compared with a 2.6 % failure rate in the long-nail group (p = 0.191). There was a 3.33 % secondary femur fracture rate in the short-nail group, compared with none in the long-nail cohort (p = 0.054). The rate of proximal fixation failure was 1.67 % for the short-nail group and 2.0 % in the long-nail group (p = 0.406). Our data suggests equivocal outcomes as measured by similar catastrophic failure rate between both short and long cephalomedullary nails for intertrochanteric femur fractures. However, there was an increased risk of secondary femur fracture with short cephalomedullary nails when compared to long nails that approached statistical significance.

Resilience Design Patterns - A Structured Approach to Resilience at Extreme Scale (version 1.0)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hukerikar, Saurabh; Engelmann, Christian

Reliability is a serious concern for future extreme-scale high-performance computing (HPC) systems. Projections based on the current generation of HPC systems and technology roadmaps suggest that very high fault rates in future systems. The errors resulting from these faults will propagate and generate various kinds of failures, which may result in outcomes ranging from result corruptions to catastrophic application crashes. Practical limits on power consumption in HPC systems will require future systems to embrace innovative architectures, increasing the levels of hardware and software complexities. The resilience challenge for extreme-scale HPC systems requires management of various hardware and software technologies thatmore » are capable of handling a broad set of fault models at accelerated fault rates. These techniques must seek to improve resilience at reasonable overheads to power consumption and performance. While the HPC community has developed various solutions, application-level as well as system-based solutions, the solution space of HPC resilience techniques remains fragmented. There are no formal methods and metrics to investigate and evaluate resilience holistically in HPC systems that consider impact scope, handling coverage, and performance & power eciency across the system stack. Additionally, few of the current approaches are portable to newer architectures and software ecosystems, which are expected to be deployed on future systems. In this document, we develop a structured approach to the management of HPC resilience based on the concept of resilience-based design patterns. A design pattern is a general repeatable solution to a commonly occurring problem. We identify the commonly occurring problems and solutions used to deal with faults, errors and failures in HPC systems. The catalog of resilience design patterns provides designers with reusable design elements. We define a design framework that enhances our understanding of the important constraints and opportunities for solutions deployed at various layers of the system stack. The framework may be used to establish mechanisms and interfaces to coordinate flexible fault management across hardware and software components. The framework also enables optimization of the cost-benefit trade-os among performance, resilience, and power consumption. The overall goal of this work is to enable a systematic methodology for the design and evaluation of resilience technologies in extreme-scale HPC systems that keep scientific applications running to a correct solution in a timely and cost-ecient manner in spite of frequent faults, errors, and failures of various types.« less

Toward a Fault Tolerant Architecture for Vital Medical-Based Wearable Computing.

PubMed

Abdali-Mohammadi, Fardin; Bajalan, Vahid; Fathi, Abdolhossein

2015-12-01

Advancements in computers and electronic technologies have led to the emergence of a new generation of efficient small intelligent systems. The products of such technologies might include Smartphones and wearable devices, which have attracted the attention of medical applications. These products are used less in critical medical applications because of their resource constraint and failure sensitivity. This is due to the fact that without safety considerations, small-integrated hardware will endanger patients' lives. Therefore, proposing some principals is required to construct wearable systems in healthcare so that the existing concerns are dealt with. Accordingly, this paper proposes an architecture for constructing wearable systems in critical medical applications. The proposed architecture is a three-tier one, supporting data flow from body sensors to cloud. The tiers of this architecture include wearable computers, mobile computing, and mobile cloud computing. One of the features of this architecture is its high possible fault tolerance due to the nature of its components. Moreover, the required protocols are presented to coordinate the components of this architecture. Finally, the reliability of this architecture is assessed by simulating the architecture and its components, and other aspects of the proposed architecture are discussed.

Effects of Augmented Reality on Student Achievement and Self-Efficacy in Vocational Education and Training

ERIC Educational Resources Information Center

Sirakaya, Mustafa; Cakmak, Ebru Kilic

2018-01-01

This study aimed to test the impact of augmented reality (AR) use on student achievement and self-efficacy in vocational education and training. For this purpose, a marker-based AR application, called HardwareAR, was developed. HardwareAR provides information about characteristics of hardware components, ports and assembly. The research design was…

Space biology initiative program definition review. Trade study 3: Hardware miniaturization versus cost

NASA Technical Reports Server (NTRS)

Jackson, L. Neal; Crenshaw, John, Sr.; Davidson, William L.; Herbert, Frank J.; Bilodeau, James W.; Stoval, J. Michael; Sutton, Terry

1989-01-01

The optimum hardware miniaturization level with the lowest cost impact for space biology hardware was determined. Space biology hardware and/or components/subassemblies/assemblies which are the most likely candidates for application of miniaturization are to be defined and relative cost impacts of such miniaturization are to be analyzed. A mathematical or statistical analysis method with the capability to support development of parametric cost analysis impacts for levels of production design miniaturization are provided.

The Application of Acoustic Measurements and Audio Recordings for Diagnosis of In-Flight Hardware Anomalies

NASA Technical Reports Server (NTRS)

Welsh, David; Denham, Samuel; Allen, Christopher

2011-01-01

In many cases, an initial symptom of hardware malfunction is unusual or unexpected acoustic noise. Many industries such as automotive, heating and air conditioning, and petro-chemical processing use noise and vibration data along with rotating machinery analysis techniques to identify noise sources and correct hardware defects. The NASA/Johnson Space Center Acoustics Office monitors the acoustic environment of the International Space Station (ISS) through periodic sound level measurement surveys. Trending of the sound level measurement survey results can identify in-flight hardware anomalies. The crew of the ISS also serves as a "detection tool" in identifying unusual hardware noises; in these cases the spectral analysis of audio recordings made on orbit can be used to identify hardware defects that are related to rotating components such as fans, pumps, and compressors. In this paper, three examples of the use of sound level measurements and audio recordings for the diagnosis of in-flight hardware anomalies are discussed: identification of blocked inter-module ventilation (IMV) ducts, diagnosis of abnormal ISS Crew Quarters rack exhaust fan noise, and the identification and replacement of a defective flywheel assembly in the Treadmill with Vibration Isolation (TVIS) hardware. In each of these examples, crew time was saved by identifying the off nominal component or condition that existed and in directing in-flight maintenance activities to address and correct each of these problems.

Fastening hardware to honeycomb panels

NASA Technical Reports Server (NTRS)

Kenger, A.

1979-01-01

Adhesive bonding reduces likelihood of skin failure due to excessive forces or torques by utilizing an adhesive to honeycomb skin. Concept is useful in other applications of composites such as aircraft, automobiles, and home appliances.

Independent Orbiter Assessment (IOA): Assessment of the purge, vent and drain subsystem

NASA Technical Reports Server (NTRS)

Bynum, M. C., III

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Purge, Vent and Drain (PV and D) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter PV and D hardware. The PV and D Subsystem controls the environment of unpressurized compartments and window cavities, senses hazardous gases, and purges Orbiter/ET disconnect.

Stochastic availability analysis of operational data systems in the Deep Space Network

NASA Technical Reports Server (NTRS)

Issa, T. N.

1991-01-01

Existing availability models of standby redundant systems consider only an operator's performance and its interaction with the hardware performance. In the case of operational data systems in the Deep Space Network (DSN), in addition to an operator system interface, a controller reconfigures the system and links a standby unit into the network data path upon failure of the operating unit. A stochastic (Markovian) process technique is used to model and analyze the availability performance and occurrence of degradation due to partial failures are quantitatively incorporated into the model. Exact expressions of the steady state availability and proportion degraded performance measures are derived for the systems under study. The interaction among the hardware, operator, and controller performance parameters and that interaction's effect on data availability are evaluated and illustrated for an operational data processing system.

Independent Orbiter Assessment (IOA): Assessment of the orbital maneuvering subsystem, volume 2

NASA Technical Reports Server (NTRS)

Haufler, W. A.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Orbital Maneuvering System (OMS) hardware and electrical power distribution and control (EPD and C), generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline. This report documents the results of that comparison for the Orbiter OMS hardware and EPD and C systems. Volume 2 continues the presentation of IOA worksheets and contains the critical items list and the NASA FMEA to IOA worksheet cross reference and recommendations.

Independent Orbiter Assessment (IOA): Assessment of the extravehicular mobility unit, volume 2

NASA Technical Reports Server (NTRS)

Raffaelli, Gary G.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort performed an independent analysis of the Extravehicular Mobility Unit (EMU) hardware and system, generating draft failure modes criticalities and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the most recent proposed Post 51-L NASA FMEA/CIL baseline. A resolution of each discrepancy from the comparison was provided through additional analysis as required. This report documents the results of that comparison for the Orbiter EMU hardware. Volume 2 continues the presentation of IOA analysis worksheets and contains the potential critical items list and NASA FMEA to IOA worksheet cross references and recommendations.

Space flight requirements for fiber optic components: qualification testing and lessons learned

NASA Astrophysics Data System (ADS)

Ott, Melanie N.; Jin, Xiaodan Linda; Chuska, Richard; Friedberg, Patricia; Malenab, Mary; Matuszeski, Adam

2006-04-01

"Qualification" of fiber optic components holds a very different meaning than it did ten years ago. In the past, qualification meant extensive prolonged testing and screening that led to a programmatic method of reliability assurance. For space flight programs today, the combination of using higher performance commercial technology, with shorter development schedules and tighter mission budgets makes long term testing and reliability characterization unfeasible. In many cases space flight missions will be using technology within years of its development and an example of this is fiber laser technology. Although the technology itself is not a new product the components that comprise a fiber laser system change frequently as processes and packaging changes occur. Once a process or the materials for manufacturing a component change, even the data that existed on its predecessor can no longer provide assurance on the newer version. In order to assure reliability during a space flight mission, the component engineer must understand the requirements of the space flight environment as well as the physics of failure of the components themselves. This can be incorporated into an efficient and effective testing plan that "qualifies" a component to specific criteria defined by the program given the mission requirements and the component limitations. This requires interaction at the very initial stages of design between the system design engineer, mechanical engineer, subsystem engineer and the component hardware engineer. Although this is the desired interaction what typically occurs is that the subsystem engineer asks the components or development engineers to meet difficult requirements without knowledge of the current industry situation or the lack of qualification data. This is then passed on to the vendor who can provide little help with such a harsh set of requirements due to high cost of testing for space flight environments. This presentation is designed to guide the engineers of design, development and components, and vendors of commercial components with how to make an efficient and effective qualification test plan with some basic generic information about many space flight requirements. Issues related to the physics of failure, acceptance criteria and lessons learned will also be discussed to assist with understanding how to approach a space flight mission in an ever changing commercial photonics industry.

Space Flight Requirements for Fiber Optic Components; Qualification Testing and Lessons Learned

NASA Technical Reports Server (NTRS)

Ott, Melanie N.; Jin, Xiaodan Linda; Chuska, Richard; Friedberg, Patricia; Malenab, Mary; Matuszeski, Adam

2007-01-01

"Qualification" of fiber optic components holds a very different meaning than it did ten years ago. In the past, qualification meant extensive prolonged testing and screening that led to a programmatic method of reliability assurance. For space flight programs today, the combination of using higher performance commercial technology, with shorter development schedules and tighter mission budgets makes long term testing and reliability characterization unfeasible. In many cases space flight missions will be using technology within years of its development and an example of this is fiber laser technology. Although the technology itself is not a new product the components that comprise a fiber laser system change frequently as processes and packaging changes occur. Once a process or the materials for manufacturing a component change, even the data that existed on its predecessor can no longer provide assurance on the newer version. In order to assure reliability during a space flight mission, the component engineer must understand the requirements of the space flight environment as well as the physics of failure of the components themselves. This can be incorporated into an efficient and effective testing plan that "qualifies" a component to specific criteria defined by the program given the mission requirements and the component limitations. This requires interaction at the very initial stages of design between the system design engineer, mechanical engineer, subsystem engineer and the component hardware engineer. Although this is the desired interaction what typically occurs is that the subsystem engineer asks the components or development engineers to meet difficult requirements without knowledge of the current industry situation or the lack of qualification data. This is then passed on to the vendor who can provide little help with such a harsh set of requirements due to high cost of testing for space flight environments. This presentation is designed to guide the engineers of design, development and components, and vendors of commercial components with how to make an efficient and effective qualification test plan with some basic generic information about many space flight requirements. Issues related to the physics of failure, acceptance criteria and lessons learned will also be discussed to assist with understanding how to approach a space flight mission in an ever changing commercial photonics industry.

Independent Orbiter Assessment (IOA): Assessment of the rudder/speed brake subsystem FMEA/CIL

NASA Technical Reports Server (NTRS)

Wilson, R. E.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Rudder/Speed Brake (RSB) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline along with the proposed Post 51-L CIL updates included. A resolution of each discrepancy from the comparison was provided through additional analysis as required. This report documents the results of that comparison for the Orbiter RSB hardware. The IOA product for the RSB analysis consisted of 38 failure mode worksheets that resulted in 27 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 34 FMEAs and 18 CIL items. This comparison produced agreement on all CIL items. Based on the Pre 51-L baseline, all non-CIL FMEAs were also in agreement.

Independent Orbiter Assessment (IOA): Assessment of the electrical power distribution and control subsystem, volume 1

NASA Technical Reports Server (NTRS)

Schmeckpeper, K. R.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA first completed an analysis of the Electrical Power Distribution and Control (EPD and C) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter EPD and C hardware. The IOA product for the EPD and C analysis consisted of 1671 failure mode analysis worksheets that resulted in 468 potential critical items being identified. Comparison was made to the proposed NASA Post 51-L baseline which consisted of FMEAs and 158 CIL items. Volume 1 contains the EPD and C subsystem description, analysis results, ground rules and assumptions, and some of the IOA worksheets.

Independent Orbiter Assessment (IOA): Assessment of the manned maneuvering unit

NASA Technical Reports Server (NTRS)

Huynh, M.; Duffy, R. E.; Saiidi, M. J.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Manned Maneuvering Unit (MMU) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contain within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed Martin Marietta FMEA/CIL Post 51-L updates. A discussion of each discrepancy from the comparison is provided through additional analysis as required. These discrepancies were flagged as issues, and recommendations were made based on the FMEA data available at the time. The results of this comparison for the Orbiter MMU hardware are documented. The IOA product for the MMU analysis consisted of 204 failure mode worksheets that resulted in 95 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 179 FMEAs and 110 CIL items. This comparison produced agreement on all 121 FMEAs which caused differences in 92 CIL items.

Independent Orbiter Assessment (IOA): Assessment of the landing/deceleration (LDG/DEC) subsystem FMEA/CIL

NASA Technical Reports Server (NTRS)

Odonnell, R. A.; Weissinger, D.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Landing/Deceleration (LDG/DEC) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter LDG/DEC hardware. The IOA product for the LDG/DEC analysis consisted of 259 failure mode worksheets that resulted in 124 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 267 FMEA's and 120 CIL items. This comparison produced agreement on all but 75 FMEA's which caused differences in 51 CIL items.

Independent Orbiter Assessment (IOA): Assessment of the ascent thrust vector control actuator subsystem FMEA/CIL

NASA Technical Reports Server (NTRS)

Wilson, R. E.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Ascent Thrust Vector Control Actuator (ATVD) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter ATVC hardware. The IOA product for the ATVC actuator analysis consisted of 25 failure mode worksheets that resulted in 16 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 21 FMEAs and 13 CIL items. This comparison produced agreement on all CIL items. Based on the Pre 51-L baseline, all non-CIL FMEAs were also in agreement.

Control of Flexible Systems in the Presence of Failures

NASA Technical Reports Server (NTRS)

Magahami, Peiman G.; Cox, David E.; Bauer, Frank H. (Technical Monitor)

2001-01-01

Control of flexible systems under degradation or failure of sensors/actuators is considered. A Linear Matrix Inequality framework is used to synthesize H(sub infinity)-based controllers, which provide good disturbance rejection while capable of tolerating real parameter uncertainties in the system model, as well as potential degradation or failure of the control system hardware. In this approach, a one-at-a-time failure scenario is considered, wherein no more than one sensor or actuator is allowed to fail at any given time. A numerical example involving control synthesis for a two-dimensional flexible system is presented to demonstrate the feasibility of the proposed approach.

SU-E-T-421: Failure Mode and Effects Analysis (FMEA) of Xoft Electronic Brachytherapy for the Treatment of Superficial Skin Cancers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoisak, J; Manger, R; Dragojevic, I

Purpose: To perform a failure mode and effects analysis (FMEA) of the process for treating superficial skin cancers with the Xoft Axxent electronic brachytherapy (eBx) system, given the recent introduction of expanded quality control (QC) initiatives at our institution. Methods: A process map was developed listing all steps in superficial treatments with Xoft eBx, from the initial patient consult to the completion of the treatment course. The process map guided the FMEA to identify the failure modes for each step in the treatment workflow and assign Risk Priority Numbers (RPN), calculated as the product of the failure mode’s probability ofmore » occurrence (O), severity (S) and lack of detectability (D). FMEA was done with and without the inclusion of recent QC initiatives such as increased staffing, physics oversight, standardized source calibration, treatment planning and documentation. The failure modes with the highest RPNs were identified and contrasted before and after introduction of the QC initiatives. Results: Based on the FMEA, the failure modes with the highest RPN were related to source calibration, treatment planning, and patient setup/treatment delivery (Fig. 1). The introduction of additional physics oversight, standardized planning and safety initiatives such as checklists and time-outs reduced the RPNs of these failure modes. High-risk failure modes that could be mitigated with improved hardware and software interlocks were identified. Conclusion: The FMEA analysis identified the steps in the treatment process presenting the highest risk. The introduction of enhanced QC initiatives mitigated the risk of some of these failure modes by decreasing their probability of occurrence and increasing their detectability. This analysis demonstrates the importance of well-designed QC policies, procedures and oversight in a Xoft eBx programme for treatment of superficial skin cancers. Unresolved high risk failure modes highlight the need for non-procedural quality initiatives such as improved planning software and more robust hardware interlock systems.« less

Identification marking by means of laser peening

DOEpatents

Hackel, Lloyd A.; Dane, C. Brent; Harris, Fritz

2002-01-01

The invention is a method and apparatus for marking components by inducing a shock wave on the surface that results in an indented (strained) layer and a residual compressive stress in the surface layer. One embodiment of the laser peenmarking system rapidly imprints, with single laser pulses, a complete identification code or three-dimensional pattern and leaves the surface in a state of deep residual compressive stress. A state of compressive stress in parts made of metal or other materials is highly desirable to make them resistant to fatigue failure and stress corrosion cracking. This process employs a laser peening system and beam spatial modulation hardware or imaging technology that can be setup to impress full three dimensional patterns into metal surfaces at the pulse rate of the laser, a rate that is at least an order of magnitude faster than competing marking technologies.

The First Development of Human Factors Engineering Requirements for Application to Ground Task Design for a NASA Flight Program

NASA Technical Reports Server (NTRS)

Dischinger, H. Charles, Jr.; Stambolian, Damon B.; Miller, Darcy H.

2008-01-01

The National Aeronautics and Space Administration has long applied standards-derived human engineering requirements to the development of hardware and software for use by astronauts while in flight. The most important source of these requirements has been NASA-STD-3000. While there have been several ground systems human engineering requirements documents, none has been applicable to the flight system as handled at NASA's launch facility at Kennedy Space Center. At the time of the development of previous human launch systems, there were other considerations that were deemed more important than developing worksites for ground crews; e.g., hardware development schedule and vehicle performance. However, experience with these systems has shown that failure to design for ground tasks has resulted in launch schedule delays, ground operations that are more costly than they might be, and threats to flight safety. As the Agency begins the development of new systems to return humans to the moon, the new Constellation Program is addressing this issue with a new set of human engineering requirements. Among these requirements is a subset that will apply to the design of the flight components and that is intended to assure ground crew success in vehicle assembly and maintenance tasks. These requirements address worksite design for usability and for ground crew safety.

Ultra-low-power and robust digital-signal-processing hardware for implantable neural interface microsystems.

PubMed

Narasimhan, S; Chiel, H J; Bhunia, S

2011-04-01

Implantable microsystems for monitoring or manipulating brain activity typically require on-chip real-time processing of multichannel neural data using ultra low-power, miniaturized electronics. In this paper, we propose an integrated-circuit/architecture-level hardware design framework for neural signal processing that exploits the nature of the signal-processing algorithm. First, we consider different power reduction techniques and compare the energy efficiency between the ultra-low frequency subthreshold and conventional superthreshold design. We show that the superthreshold design operating at a much higher frequency can achieve comparable energy dissipation by taking advantage of extensive power gating. It also provides significantly higher robustness of operation and yield under large process variations. Next, we propose an architecture level preferential design approach for further energy reduction by isolating the critical computation blocks (with respect to the quality of the output signal) and assigning them higher delay margins compared to the noncritical ones. Possible delay failures under parameter variations are confined to the noncritical components, allowing graceful degradation in quality under voltage scaling. Simulation results using prerecorded neural data from the sea-slug (Aplysia californica) show that the application of the proposed design approach can lead to significant improvement in total energy, without compromising the output signal quality under process variations, compared to conventional design approaches.

Empirical cost models for estimating power and energy consumption in database servers

NASA Astrophysics Data System (ADS)

Valdivia Garcia, Harold Dwight

The explosive growth in the size of data centers, coupled with the widespread use of virtualization technology has brought power and energy consumption as major concerns for data center administrators. Provisioning decisions must take into consideration not only target application performance but also the power demands and total energy consumption incurred by the hardware and software to be deployed at the data center. Failure to do so will result in damaged equipment, power outages, and inefficient operation. Since database servers comprise one of the most popular and important server applications deployed in such facilities, it becomes necessary to have accurate cost models that can predict the power and energy demands that each database workloads will impose in the system. In this work we present an empirical methodology to estimate the power and energy cost of database operations. Our methodology uses multiple-linear regression to derive accurate cost models that depend only on readily available statistics such as selectivity factors, tuple size, numbers columns and relational cardinality. Moreover, our method does not need measurement of individual hardware components, but rather total power and energy consumption measured at a server. We have implemented our methodology, and ran experiments with several server configurations. Our experiments indicate that we can predict power and energy more accurately than alternative methods found in the literature.

Feature-based component model for design of embedded systems

NASA Astrophysics Data System (ADS)

Zha, Xuan Fang; Sriram, Ram D.

2004-11-01

An embedded system is a hybrid of hardware and software, which combines software's flexibility and hardware real-time performance. Embedded systems can be considered as assemblies of hardware and software components. An Open Embedded System Model (OESM) is currently being developed at NIST to provide a standard representation and exchange protocol for embedded systems and system-level design, simulation, and testing information. This paper proposes an approach to representing an embedded system feature-based model in OESM, i.e., Open Embedded System Feature Model (OESFM), addressing models of embedded system artifacts, embedded system components, embedded system features, and embedded system configuration/assembly. The approach provides an object-oriented UML (Unified Modeling Language) representation for the embedded system feature model and defines an extension to the NIST Core Product Model. The model provides a feature-based component framework allowing the designer to develop a virtual embedded system prototype through assembling virtual components. The framework not only provides a formal precise model of the embedded system prototype but also offers the possibility of designing variation of prototypes whose members are derived by changing certain virtual components with different features. A case study example is discussed to illustrate the embedded system model.

Providing Self-Healing Ability for Wireless Sensor Node by Using Reconfigurable Hardware

PubMed Central

Yuan, Shenfang; Qiu, Lei; Gao, Shang; Tong, Yao; Yang, Weiwei

2012-01-01

Wireless sensor networks (WSNs) have received tremendous attention over the past ten years. In engineering applications of WSNs, a number of sensor nodes are usually spread across some specific geographical area. Some of these nodes have to work in harsh environments. Dependability of the Wireless Sensor Network (WSN) is very important for its successful applications in the engineering area. In ordinary research, when a node has a failure, it is usually discarded and the network is reorganized to ensure the normal operation of the WSN. Using appropriate WSN re-organization methods, though the sensor networks can be reorganized, this causes additional maintenance costs and sometimes still decreases the function of the networks. In those situations where the sensor networks cannot be reorganized, the performance of the whole WSN will surely be degraded. In order to ensure the reliable and low cost operation of WSNs, a method to develop a wireless sensor node with self-healing ability based on reconfigurable hardware is proposed in this paper. Two self-healing WSN node realization paradigms based on reconfigurable hardware are presented, including a redundancy-based self-healing paradigm and a whole FPAA/FPGA based self-healing paradigm. The nodes designed with the self-healing ability can dynamically change their node configurations to repair the nodes' hardware failures. To demonstrate these two paradigms, a strain sensor node is adopted as an illustration to show the concepts. Two strain WSN sensor nodes with self-healing ability are developed respectively according to the proposed self-healing paradigms. Evaluation experiments on self-healing ability and power consumption are performed. Experimental results show that the developed nodes can self-diagnose the failures and recover to a normal state automatically. The research presented can improve the robustness of WSNs and reduce the maintenance cost of WSNs in engineering applications. PMID:23202176

Failure Analysis at the Kennedy Space Center

NASA Technical Reports Server (NTRS)

Salazar, Victoria L.; Wright, M. Clara

2010-01-01

History has shown that failures occur in every engineering endeavor, and what we learn from those failures contributes to the knowledge base to safely complete future missions. The necessity of failure analysis is at its apex at the end of one aged program and at the beginning of a new and untested program. The information that we gain through failure analysis corrects the deficiencies in the current vehicle to make the next generation of vehicles more efficient and safe. The Failure Analysis and Materials Evaluation Branch in the Materials Science Division at the Kennedy Space Center performs metallurgical, mechanical, electrical, and non-metallic materials failure analyses and accident investigations on both flight hardware and ground support equipment for the Space Shuttle, International Space Station, Constellation, and Launch Services Programs. This paper will explore a variety of failure case studies at the Kennedy Space Center and the lessons learned that can be applied in future programs.

Designing for Reliability and Robustness

NASA Technical Reports Server (NTRS)

Svetlik, Randall G.; Moore, Cherice; Williams, Antony

2017-01-01

Long duration spaceflight has a negative effect on the human body, and exercise countermeasures are used on-board the International Space Station (ISS) to minimize bone and muscle loss, combatting these effects. Given the importance of these hardware systems to the health of the crew, this equipment must continue to be readily available. Designing spaceflight exercise hardware to meet high reliability and availability standards has proven to be challenging throughout the time the crewmembers have been living on ISS beginning in 2000. Furthermore, restoring operational capability after a failure is clearly time-critical, but can be problematic given the challenges of troubleshooting the problem from 220 miles away. Several best-practices have been leveraged in seeking to maximize availability of these exercise systems, including designing for robustness, implementing diagnostic instrumentation, relying on user feedback, and providing ample maintenance and sparing. These factors have enhanced the reliability of hardware systems, and therefore have contributed to keeping the crewmembers healthy upon return to Earth. This paper will review the failure history for three spaceflight exercise countermeasure systems identifying lessons learned that can help improve future systems. Specifically, the Treadmill with Vibration Isolation and Stabilization System (TVIS), Cycle Ergometer with Vibration Isolation and Stabilization System (CEVIS), and the Advanced Resistive Exercise Device (ARED) will be reviewed, analyzed, and conclusions identified so as to provide guidance for improving future exercise hardware designs. These lessons learned, paired with thorough testing, offer a path towards reduced system down-time.

Qualification of Engineering Camera for Long-Duration Deep Space Missions

NASA Technical Reports Server (NTRS)

Ramesham, Rajeshuni; Maki, Justin N.; Pourangi, Ali M.; Lee, Steven W.

2012-01-01

Qualification and verification of advanced electronic packaging and interconnect technologies, and various other types of hardware elements for the Mars Exploration Rover s Spirit and Opportunity (MER)/Mars Science Laboratory (MSL) flight projects, has been performed to enhance the mission assurance. The qualification of hardware (engineering camera) under extreme cold temperatures has been performed with reference to various Mars-related project requirements. The flight-like packages, sensors, and subassemblies have been selected for the study to survive three times the total number of expected diurnal temperature cycles resulting from all environmental and operational exposures occurring over the life of the flight hardware, including all relevant manufacturing, ground operations, and mission phases. Qualification has been performed by subjecting above flight-like hardware to the environmental temperature extremes, and assessing any structural failures or degradation in electrical performance due to either overstress or thermal cycle fatigue. Engineering camera packaging designs, charge-coupled devices (CCDs), and temperature sensors were successfully qualified for MER and MSL per JPL design principles. Package failures were observed during qualification processes and the package redesigns were then made to enhance the reliability and subsequent mission assurance. These results show the technology certainly is promising for MSL, and especially for longterm extreme temperature missions to the extreme temperature conditions. The engineering camera has been completely qualified for the MSL project, with the proven ability to survive on Mars for 2010 sols, or 670 sols times three. Finally, the camera continued to be functional, even after 2010 thermal cycles.

Study of metal whiskers growth and mitigation technique using additive manufacturing

NASA Astrophysics Data System (ADS)

Gullapalli, Vikranth

For years, the alloy of choice for electroplating electronic components has been tin-lead (Sn-Pb) alloy. However, the legislation established in Europe on July 1, 2006, required significant lead (Pb) content reductions from electronic hardware due to its toxic nature. A popular alternative for coating electronic components is pure tin (Sn). However, pure tin has the tendency to spontaneously grow electrically conductive Sn whisker during storage. Sn whisker is usually a pure single crystal tin with filament or hair-like structures grown directly from the electroplated surfaces. Sn whisker is highly conductive, and can cause short circuits in electronic components, which is a very significant reliability problem. The damages caused by Sn whisker growth are reported in very critical applications such as aircraft, spacecraft, satellites, and military weapons systems. They are also naturally very strong and are believed to grow from compressive stresses developed in the Sn coating during deposition or over time. The new directive, even though environmentally friendly, has placed all lead-free electronic devices at risk because of whisker growth in pure tin. Additionally, interest has occurred about studying the nature of other metal whiskers such as zinc (Zn) whiskers and comparing their behavior to that of Sn whiskers. Zn whiskers can be found in flooring of data centers which can get inside electronic systems during equipment reorganization and movement and can also cause systems failure. Even though the topic of metal whiskers as reliability failure has been around for several decades to date, there is no successful method that can eliminate their growth. This thesis will give further insights towards the nature and behavior of Sn and Zn whiskers growth, and recommend a novel manufacturing technique that has potential to mitigate metal whiskers growth and extend life of many electronic devices.

Advanced Data Acquisition Systems

NASA Technical Reports Server (NTRS)

Perotti, J.

2003-01-01

Current and future requirements of the aerospace sensors and transducers field make it necessary for the design and development of new data acquisition devices and instrumentation systems. New designs are sought to incorporate self-health, self-calibrating, self-repair capabilities, allowing greater measurement reliability and extended calibration cycles. With the addition of power management schemes, state-of-the-art data acquisition systems allow data to be processed and presented to the users with increased efficiency and accuracy. The design architecture presented in this paper displays an innovative approach to data acquisition systems. The design incorporates: electronic health self-check, device/system self-calibration, electronics and function self-repair, failure detection and prediction, and power management (reduced power consumption). These requirements are driven by the aerospace industry need to reduce operations and maintenance costs, to accelerate processing time and to provide reliable hardware with minimum costs. The project's design architecture incorporates some commercially available components identified during the market research investigation like: Field Programmable Gate Arrays (FPGA) Programmable Analog Integrated Circuits (PAC IC) and Field Programmable Analog Arrays (FPAA); Digital Signal Processing (DSP) electronic/system control and investigation of specific characteristics found in technologies like: Electronic Component Mean Time Between Failure (MTBF); and Radiation Hardened Component Availability. There are three main sections discussed in the design architecture presented in this document. They are the following: (a) Analog Signal Module Section, (b) Digital Signal/Control Module Section and (c) Power Management Module Section. These sections are discussed in detail in the following pages. This approach to data acquisition systems has resulted in the assignment of patent rights to Kennedy Space Center under U.S. patent # 6,462,684. Furthermore, NASA KSC commercialization office has issued licensing rights to Circuit Avenue Netrepreneurs, LLC , a minority-owned business founded in 1999 located in Camden, NJ.

Independent Orbiter Assessment (IOA): Analysis of the rudder/speed brake subsystem

NASA Technical Reports Server (NTRS)

Wilson, R. E.; Riccio, J. R.

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbiter Rudder/Speedbrake Actuation Mechanism is documented. The function of the Rudder/Speedbrake (RSB) is to provide directional control and to provide a means of energy control during entry. The system consists of two panels on a vertical hinge mounted on the aft part of the vertical stabilizer. These two panels move together to form a rudder but split apart to make a speedbrake. The Rudder/Speedbrake Actuation Mechanism consists of the following elements: (1) Power Drive Unit (PDU) which is composed of hydraulic valve module and a hydraulic motor-powered gearbox which contains differentials and mixer gears to provide PDU torque output; (2) four geared rotary actuators which apply the PDU generated torque to the rudder/speedbrake panels; and (3) ten torque shafts which join the PDU to the rotary actuators and interconnect the four rotary actuators. Each level of hardware was evaluated and analyzed for possible failures and causes. Criticality was assigned based upon the severity of the effect for each failure mode. Critical RSB failures which result in potential loss of vehicle control were mainly due to loss of hydraulic fluid, fluid contaminators, and mechanical failures in gears and shafts.

Digital echocardiography 2002: now is the time

NASA Technical Reports Server (NTRS)

Thomas, James D.; Greenberg, Neil L.; Garcia, Mario J.

2002-01-01

The ability to acquire echocardiographic images digitally, store and transfer these data using the DICOM standard, and routinely analyze examinations exists today and allows the implementation of a digital echocardiography laboratory. The purpose of this review article is to outline the critical components of a digital echocardiography laboratory, discuss general strategies for implementation, and put forth some of the pitfalls that we have encountered in our own implementation. The major components of the digital laboratory include (1) digital echocardiography machines with network output, (2) a switched high-speed network, (3) a high throughput server with abundant local storage, (4) a reliable low-cost archive, (5) software to manage information, and (6) support mechanisms for software and hardware. Implementation strategies can vary from a complete vendor solution providing all components (hardware, software, support), to a strategy similar to our own where standard computer and networking hardware are used with specialized software for management of image and measurement information.

Evaluation of wheelchair back support crashworthiness: combination wheelchair back support surfaces and attachment hardware.

PubMed

Ha, D; Bertocci, G; Deemer, E; van Roosmalen, L; Karg, P

2000-01-01

Automotive seats are tested for compliance with federal motor vehicle safety standards (FMVSS) to assure safety during impact. Many wheelchair users rely upon their wheelchairs to serve as vehicle seats. However, the crashworthiness of these wheelchairs during impact is often unknown. This study evaluated the crashworthiness of five combinations of wheelchair back support surfaces and attachment hardware using a static test procedure simulating crash loading conditions. The crashworthiness was tested by applying a simulated rearward load to each seat-back system. The magnitude of the applied load was established through computer simulation and biodynamic calculations. None of the five tested wheelchair back supports withstood the simulated crash loads. All failures were associated with attachment hardware.

Similarity constraints in testing of cooled engine parts

NASA Technical Reports Server (NTRS)

Colladay, R. S.; Stepka, F. S.

1974-01-01

A study is made of the effect of testing cooled parts of current and advanced gas turbine engines at the reduced temperature and pressure conditions which maintain similarity with the engine environment. Some of the problems facing the experimentalist in evaluating heat transfer and aerodynamic performance when hardware is tested at conditions other than the actual engine environment are considered. Low temperature and pressure test environments can simulate the performance of actual size prototype engine hardware within the tolerance of experimental accuracy if appropriate similarity conditions are satisfied. Failure to adhere to these similarity constraints because of test facility limitations or other reasons, can result in a number of serious errors in projecting the performance of test hardware to engine conditions.

Reliability of Beam Loss Monitor Systems for the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Guaglio, G.; Dehning, B.; Santoni, C.

2005-06-01

The increase of beam energy and beam intensity, together with the use of super conducting magnets, opens new failure scenarios and brings new criticalities for the whole accelerator protection system. For the LHC beam loss protection system, the failure rate and the availability requirements have been evaluated using the Safety Integrity Level (SIL) approach. A downtime cost evaluation is used as input for the SIL approach. The most critical systems, which contribute to the final SIL value, are the dump system, the interlock system, the beam loss monitors system, and the energy monitor system. The Beam Loss Monitors System (BLMS) is critical for short and intense particles losses at 7 TeV and assisted by the Fast Beam Current Decay Monitors at 450 GeV. At medium and higher loss time it is assisted by other systems, such as the quench protection system and the cryogenic system. For BLMS, hardware and software have been evaluated in detail. The reliability input figures have been collected using historical data from the SPS, using temperature and radiation damage experimental data as well as using standard databases. All the data has been processed by reliability software (Isograph). The analysis spaces from the components data to the system configuration.

Demonstration Advanced Avionics System (DAAS), Phase 1

NASA Technical Reports Server (NTRS)

Bailey, A. J.; Bailey, D. G.; Gaabo, R. J.; Lahn, T. G.; Larson, J. C.; Peterson, E. M.; Schuck, J. W.; Rodgers, D. L.; Wroblewski, K. A.

1981-01-01

Demonstration advanced anionics system (DAAS) function description, hardware description, operational evaluation, and failure mode and effects analysis (FMEA) are provided. Projected advanced avionics system (PAAS) description, reliability analysis, cost analysis, maintainability analysis, and modularity analysis are discussed.

Use of Heritage Hardware on Orion MPCV Exploration Flight Test One

NASA Technical Reports Server (NTRS)

Rains, George Edward; Cross, Cynthia D.

2012-01-01

Due to an aggressive schedule for the first space flight of an unmanned Orion capsule, currently known as Exploration Flight Test One (EFT1), combined with severe programmatic funding constraints, an effort was made within the Orion Program to identify heritage hardware, i.e., already existing, flight-certified components from previous manned space programs, which might be available for use on EFT1. With the end of the Space Shuttle Program, no current means exists to launch Multi-Purpose Logistics Modules (MPLMs) to the International Space Station (ISS), and so the inventory of many flight-certified Shuttle and MPLM components are available for other purposes. Two of these items are the MPLM cabin Positive Pressure Relief Assembly (PPRA), and the Shuttle Ground Support Equipment Heat Exchanger (GSE HX). In preparation for the utilization of these components by the Orion Program, analyses and testing of the hardware were performed. The PPRA had to be analyzed to determine its susceptibility to pyrotechnic shock, and vibration testing had to be performed, since those environments are predicted to be more severe during an Orion mission than those the hardware was originally designed to accommodate. The GSE HX had to be tested for performance with the Orion thermal working fluids, which are different from those used by the Space Shuttle. This paper summarizes the activities required in order to utilize heritage hardware for EFT1.

Use of Heritage Hardware on MPCV Exploration Flight Test One

NASA Technical Reports Server (NTRS)

Rains, George Edward; Cross, Cynthia D.

2011-01-01

Due to an aggressive schedule for the first orbital test flight of an unmanned Orion capsule, known as Exploration Flight Test One (EFT1), combined with severe programmatic funding constraints, an effort was made to identify heritage hardware, i.e., already existing, flight-certified components from previous manned space programs, which might be available for use on EFT1. With the end of the Space Shuttle Program, no current means exists to launch Multi Purpose Logistics Modules (MPLMs) to the International Space Station (ISS), and so the inventory of many flight-certified Shuttle and MPLM components are available for other purposes. Two of these items are the Shuttle Ground Support Equipment Heat Exchanger (GSE Hx) and the MPLM cabin Positive Pressure Relief Assembly (PPRA). In preparation for the utilization of these components by the Orion Program, analyses and testing of the hardware were performed. The PPRA had to be analyzed to determine its susceptibility to pyrotechnic shock, and vibration testing had to be performed, since those environments are predicted to be significantly more severe during an Orion mission than those the hardware was originally designed to accommodate. The GSE Hx had to be tested for performance with the Orion thermal working fluids, which are different from those used by the Space Shuttle. This paper summarizes the certification of the use of heritage hardware for EFT1.

Independent Orbiter Assessment (IOA): Assessment of the life support and airlock support systems, volume 2

NASA Technical Reports Server (NTRS)

Barickman, K.

1988-01-01

The McDonnell Douglas Astronautics Company (MDAC) was selected in June 1986 to perform an Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL). The IOA effort first completed an analysis of the Life Support and Airlock Support Systems (LSS and ALSS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. The discrepancies were flagged for potential future resolution. This report documents the results of that comparison for the Orbiter LSS and ALSS hardware. Volume 2 continues the presentation of IOA worksheets and contains the critical items list and NASA FMEA to IOA worksheet cross reference and recommendations.

Independent Orbiter Assessment (IOA): Assessment of the electrical power distribution and control subsystem, volume 3

NASA Technical Reports Server (NTRS)

Schmeckpeper, K. R.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA first completed an analysis of the Electrical Power Distribution and Control (EPD and C) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter EPD and C hardware. Volume 3 continues the presentation of IOA worksheets and contains the potential critical items list and the NASA FMEA to IOA worksheet cross reference and recommendations.

Bone Plating in Patients with Type III Osteogenesis Imperfecta: Results and Complications

PubMed Central

Enright, William J; Noonan, Kenneth J

2006-01-01

The results of bone plating in four children (6 femurs, 2 tibias) with osteogenesis imperfecta type III were analyzed. Average age at time of operation was 44 months. In three of the femurs, multiple platings were performed for a total of 13 bone platings in the eight bones studied. Average time to revision following plating was 27 months. Indications for revision included fracture (6), deformity (3), hardware failure (3), and nonunion (1). Other complications included one case of compartment syndrome. All eight bones were ultimately revised to elongating intramedullary Bailey-Dubow rods. Bone plating in skeletally immature patients with osteogenesis imperfecta does not provide better outcome than elongating rods. Complications from bone plating leading to revision, such as refracture or hardware failure, are higher than in those children managed with elongating rods, as previously reported in the literature. PMID:16789446

Independent Orbiter Assessment (IOA): Assessment of the atmospheric revitalization pressure control subsystem FMEA/CIL

NASA Technical Reports Server (NTRS)

Saiidi, M. J.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the atmospheric Revitalization Pressure Control Subsystem (ARPCS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL proposed Post 51-L updates based upon the CCB/PRCB presentations and an informal criticality summary listing. A discussion of each discrepancy from the comparison is provided through additional analysis as required. These discrepancies were flagged as issues, and recommendations were made based on the FMEA data available at the time. This report documents the results of that comparison for the Orbiter ARPCS hardware.

What's New for the Orbiting Carbon Observatory-2? A Summary of Changes between the Original and Re-flight Missions

NASA Astrophysics Data System (ADS)

Boland, S. W.; Kahn, P. B.

2012-12-01

The original Orbiting Carbon Observatory mission was lost in 2009 when the spacecraft failed to achieve orbit due to a launch vehicle failure. In 2010, NASA authorized a re-flight mission, known as the Orbiting Carbon Observatory-2 (OCO-2) mission, with direction to re-use the original hardware, designs, drawings, documents, and procedures wherever possible in order to minimize cost, schedule, and performance risk. During implementation, it was realized that some changes were required due to parts obsolescence, incorporation of lessons learned from the original OCO mission, and to provide optimal science return. In response to the OCO and Glory launch vehicle failures, a change in launch vehicle was also recently announced. A summary of changes, including those to hardware, orbit, and launch vehicle is provided, along with rationale, implementation approach, and impact (if any) on mission science.

Error detection method

DOEpatents

Olson, Eric J.

2013-06-11

An apparatus, program product, and method that run an algorithm on a hardware based processor, generate a hardware error as a result of running the algorithm, generate an algorithm output for the algorithm, compare the algorithm output to another output for the algorithm, and detect the hardware error from the comparison. The algorithm is designed to cause the hardware based processor to heat to a degree that increases the likelihood of hardware errors to manifest, and the hardware error is observable in the algorithm output. As such, electronic components may be sufficiently heated and/or sufficiently stressed to create better conditions for generating hardware errors, and the output of the algorithm may be compared at the end of the run to detect a hardware error that occurred anywhere during the run that may otherwise not be detected by traditional methodologies (e.g., due to cooling, insufficient heat and/or stress, etc.).

Advanced Signal Conditioners for Data-Acquisition Systems

NASA Technical Reports Server (NTRS)

Lucena, Angel; Perotti, Jose; Eckhoff, Anthony; Medelius, Pedro

2004-01-01

Signal conditioners embodying advanced concepts in analog and digital electronic circuitry and software have been developed for use in data-acquisition systems that are required to be compact and lightweight, to utilize electric energy efficiently, and to operate with high reliability, high accuracy, and high power efficiency, without intervention by human technicians. These signal conditioners were originally intended for use aboard spacecraft. There are also numerous potential terrestrial uses - especially in the fields of aeronautics and medicine, wherein it is necessary to monitor critical functions. Going beyond the usual analog and digital signal-processing functions of prior signal conditioners, the new signal conditioner performs the following additional functions: It continuously diagnoses its own electronic circuitry, so that it can detect failures and repair itself (as described below) within seconds. It continuously calibrates itself on the basis of a highly accurate and stable voltage reference, so that it can continue to generate accurate measurement data, even under extreme environmental conditions. It repairs itself in the sense that it contains a micro-controller that reroutes signals among redundant components as needed to maintain the ability to perform accurate and stable measurements. It detects deterioration of components, predicts future failures, and/or detects imminent failures by means of a real-time analysis in which, among other things, data on its present state are continuously compared with locally stored historical data. It minimizes unnecessary consumption of electric energy. The design architecture divides the signal conditioner into three main sections: an analog signal section, a digital module, and a power-management section. The design of the analog signal section does not follow the traditional approach of ensuring reliability through total redundancy of hardware: Instead, following an approach called spare parts tool box, the reliability of each component is assessed in terms of such considerations as risks of damage, mean times between failures, and the effects of certain failures on the performance of the signal conditioner as a whole system. Then, fewer or more spares are assigned for each affected component, pursuant to the results of this analysis, in order to obtain the required degree of reliability of the signal conditioner as a whole system. The digital module comprises one or more processors and field-programmable gate arrays, the number of each depending on the results of the aforementioned analysis. The digital module provides redundant control, monitoring, and processing of several analog signals. It is designed to minimize unnecessary consumption of electric energy, including, when possible, going into a low-power "sleep" mode that is implemented in firmware. The digital module communicates with external equipment via a personal-computer serial port. The digital module monitors the "health" of the rest of the signal conditioner by processing defined measurements and/or trends. It automatically makes adjustments to respond to channel failures, compensate for effects of temperature, and maintain calibration.

Reliability Evaluation of Machine Center Components Based on Cascading Failure Analysis

NASA Astrophysics Data System (ADS)

Zhang, Ying-Zhi; Liu, Jin-Tong; Shen, Gui-Xiang; Long, Zhe; Sun, Shu-Guang

2017-07-01

In order to rectify the problems that the component reliability model exhibits deviation, and the evaluation result is low due to the overlook of failure propagation in traditional reliability evaluation of machine center components, a new reliability evaluation method based on cascading failure analysis and the failure influenced degree assessment is proposed. A direct graph model of cascading failure among components is established according to cascading failure mechanism analysis and graph theory. The failure influenced degrees of the system components are assessed by the adjacency matrix and its transposition, combined with the Pagerank algorithm. Based on the comprehensive failure probability function and total probability formula, the inherent failure probability function is determined to realize the reliability evaluation of the system components. Finally, the method is applied to a machine center, it shows the following: 1) The reliability evaluation values of the proposed method are at least 2.5% higher than those of the traditional method; 2) The difference between the comprehensive and inherent reliability of the system component presents a positive correlation with the failure influenced degree of the system component, which provides a theoretical basis for reliability allocation of machine center system.

An evaluation of Skylab habitability hardware

NASA Technical Reports Server (NTRS)

Stokes, J.

1974-01-01

For effective mission performance, participants in space missions lasting 30-60 days or longer must be provided with hardware to accommodate their personal needs. Such habitability hardware was provided on Skylab. Equipment defined as habitability hardware was that equipment composing the food system, water system, sleep system, waste management system, personal hygiene system, trash management system, and entertainment equipment. Equipment not specifically defined as habitability hardware but which served that function were the Wardroom window, the exercise equipment, and the intercom system, which was occasionally used for private communications. All Skylab habitability hardware generally functioned as intended for the three missions, and most items could be considered as adequate concepts for future flights of similar duration. Specific components were criticized for their shortcomings.

Getting expert systems off the ground: Lessons learned from integrating model-based diagnostics with prototype flight hardware

NASA Technical Reports Server (NTRS)

Stephan, Amy; Erikson, Carol A.

1991-01-01

As an initial attempt to introduce expert system technology into an onboard environment, a model based diagnostic system using the TRW MARPLE software tool was integrated with prototype flight hardware and its corresponding control software. Because this experiment was designed primarily to test the effectiveness of the model based reasoning technique used, the expert system ran on a separate hardware platform, and interactions between the control software and the model based diagnostics were limited. While this project met its objective of showing that model based reasoning can effectively isolate failures in flight hardware, it also identified the need for an integrated development path for expert system and control software for onboard applications. In developing expert systems that are ready for flight, artificial intelligence techniques must be evaluated to determine whether they offer a real advantage onboard, identify which diagnostic functions should be performed by the expert systems and which are better left to the procedural software, and work closely with both the hardware and the software developers from the beginning of a project to produce a well designed and thoroughly integrated application.

Qualification Testing of Engineering Camera and Platinum Resistance Thermometer (PRT) Sensors for Mars Science Laboratory (MSL) Project under Extreme Temperatures to Assess Reliability and to Enhance Mission Assurance

NASA Technical Reports Server (NTRS)

Ramesham, Rajeshuni; Maki, Justin N.; Cucullu, Gordon C.

2008-01-01

Package Qualification and Verification (PQV) of advanced electronic packaging and interconnect technologies and various other types of qualification hardware for the Mars Exploration Rover/Mars Science Laboratory flight projects has been performed to enhance the mission assurance. The qualification of hardware (Engineering Camera and Platinum Resistance Thermometer, PRT) under extreme cold temperatures has been performed with reference to various project requirements. The flight-like packages, sensors, and subassemblies have been selected for the study to survive three times (3x) the total number of expected temperature cycles resulting from all environmental and operational exposures occurring over the life of the flight hardware including all relevant manufacturing, ground operations and mission phases. Qualification has been performed by subjecting above flight-like qual hardware to the environmental temperature extremes and assessing any structural failures or degradation in electrical performance due to either overstress or thermal cycle fatigue. Experiments of flight like hardware qualification test results have been described in this paper.

Contamination Examples and Lessons from Low Earth Orbit Experiments and Operational Hardware

NASA Technical Reports Server (NTRS)

Pippin, Gary; Finckenor, Miria M.

2009-01-01

Flight experiments flown on the Space Shuttle, the International Space Station, Mir, Skylab, and free flyers such as the Long Duration Exposure Facility, the European Retrievable Carrier, and the EFFU, provide multiple opportunities for the investigation of molecular contamination effects. Retrieved hardware from the Solar Maximum Mission satellite, Mir, and the Hubble Space Telescope has also provided the means gaining insight into contamination processes. Images from the above mentioned hardware show contamination effects due to materials processing, hardware storage, pre-flight cleaning, as well as on-orbit events such as outgassing, mechanical failure of hardware in close proximity, impacts from man-made debris, and changes due to natural environment factors.. Contamination effects include significant changes to thermal and electrical properties of thermal control surfaces, optics, and power systems. Data from several flights has been used to develop a rudimentary estimate of asymptotic values for absorptance changes due to long-term solar exposure (4000-6000 Equivalent Sun Hours) of silicone-based molecular contamination deposits of varying thickness. Recommendations and suggestions for processing changes and constraints based on the on-orbit observed results will be presented.

Savannah River Site generic data base development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blanton, C.H.; Eide, S.A.

This report describes the results of a project to improve the generic component failure data base for the Savannah River Site (SRS). A representative list of components and failure modes for SRS risk models was generated by reviewing existing safety analyses and component failure data bases and from suggestions from SRS safety analysts. Then sources of data or failure rate estimates were identified and reviewed for applicability. A major source of information was the Nuclear Computerized Library for Assessing Reactor Reliability, or NUCLARR. This source includes an extensive collection of failure data and failure rate estimates for commercial nuclear powermore » plants. A recent Idaho National Engineering Laboratory report on failure data from the Idaho Chemical Processing Plant was also reviewed. From these and other recent sources, failure data and failure rate estimates were collected for the components and failure modes of interest. This information was aggregated to obtain a recommended generic failure rate distribution (mean and error factor) for each component failure mode.« less

Integration of bridge damage detection concepts and components, volume III : wireless bridge monitoring hardware.

DOT National Transportation Integrated Search

2013-10-01

In this work, a previously developed structural health monitoring (SHM) system was advanced toward a ready-for-implementation : system. Improvements were made with respect to automated data reduction/analysis, data acquisition hardware, sensor types,...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keller, Todd M.; Benjamin, Jacob S.; Wright, Virginia L.

This paper will describe a practical methodology for understanding the cyber risk of a digital asset. This research attempts to gain a greater understanding of the cyber risk posed by a hardware-based computer asset by considering it as a sum of its hardware and software based sub-components.

Recent Technology Advances in Distributed Engine Control

NASA Technical Reports Server (NTRS)

Culley, Dennis

2017-01-01

This presentation provides an overview of the work performed at NASA Glenn Research Center in distributed engine control technology. This is control system hardware technology that overcomes engine system constraints by modularizing control hardware and integrating the components over communication networks.

The Management and Security Expert (MASE)

NASA Technical Reports Server (NTRS)

Miller, Mark D.; Barr, Stanley J.; Gryphon, Coranth D.; Keegan, Jeff; Kniker, Catherine A.; Krolak, Patrick D.

1991-01-01

The Management and Security Expert (MASE) is a distributed expert system that monitors the operating systems and applications of a network. It is capable of gleaning the information provided by the different operating systems in order to optimize hardware and software performance; recognize potential hardware and/or software failure, and either repair the problem before it becomes an emergency, or notify the systems manager of the problem; and monitor applications and known security holes for indications of an intruder or virus. MASE can eradicate much of the guess work of system management.

Pilot interaction with automated airborne decision making systems

NASA Technical Reports Server (NTRS)

Rouse, W. B.; Hammer, J. M.; Mitchell, C. M.; Morris, N. M.; Lewis, C. M.; Yoon, W. C.

1985-01-01

Progress was made in the three following areas. In the rule-based modeling area, two papers related to identification and significane testing of rule-based models were presented. In the area of operator aiding, research focused on aiding operators in novel failure situations; a discrete control modeling approach to aiding PLANT operators was developed; and a set of guidelines were developed for implementing automation. In the area of flight simulator hardware and software, the hardware will be completed within two months and initial simulation software will then be integrated and tested.

Framework for Development and Distribution of Hardware Acceleration

NASA Astrophysics Data System (ADS)

Thomas, David B.; Luk, Wayne W.

2002-07-01

This paper describes IGOL, a framework for developing reconfigurable data processing applications. While IGOL was originally designed to target imaging and graphics systems, its structure is sufficiently general to support a broad range of applications. IGOL adopts a four-layer architecture: application layer, operation layer, appliance layer and configuration layer. This architecture is intended to separate and co-ordinate both the development and execution of hardware and software components. Hardware developers can use IGOL as an instance testbed for verification and benchmarking, as well as for distribution. Software application developers can use IGOL to discover hardware accelerated data processors, and to access them in a transparent, non-hardware specific manner. IGOL provides extensive support for the RC1000-PP board via the Handel-C language, and a wide selection of image processing filters have been developed. IGOL also supplies plug-ins to enable such filters to be incorporated in popular applications such as Premiere, Winamp, VirtualDub and DirectShow. Moreover, IGOL allows the automatic use of multiple cards to accelerate an application, demonstrated using DirectShow. To enable transparent acceleration without sacrificing performance, a three-tiered COM (Component Object Model) API has been designed and implemented. This API provides a well-defined and extensible interface which facilitates the development of hardware data processors that can accelerate multiple applications.

Rapid-X - An FPGA Development Toolset Using a Custom Simulink Library for MTCA.4 Modules

NASA Astrophysics Data System (ADS)

Prędki, Paweł; Heuer, Michael; Butkowski, Łukasz; Przygoda, Konrad; Schlarb, Holger; Napieralski, Andrzej

2015-06-01

The recent introduction of advanced hardware architectures such as the Micro Telecommunications Computing Architecture (MTCA) caused a change in the approach to implementation of control schemes in many fields. The development has been moving away from traditional programming languages ( C/C++), to hardware description languages (VHDL, Verilog), which are used in FPGA development. With MATLAB/Simulink it is possible to describe complex systems with block diagrams and simulate their behavior. Those diagrams are then used by the HDL experts to implement exactly the required functionality in hardware. Both the porting of existing applications and adaptation of new ones require a lot of development time from them. To solve this, Xilinx System Generator, a toolbox for MATLAB/Simulink, allows rapid prototyping of those block diagrams using hardware modelling. It is still up to the firmware developer to merge this structure with the hardware-dependent HDL project. This prevents the application engineer from quickly verifying the proposed schemes in real hardware. The framework described in this article overcomes these challenges, offering a hardware-independent library of components that can be used in Simulink/System Generator models. The components are subsequently translated into VHDL entities and integrated with a pre-prepared VHDL project template. Furthermore, the entire implementation process is run in the background, giving the user an almost one-click path from control scheme modelling and simulation to bit-file generation. This approach allows the application engineers to quickly develop new schemes and test them in real hardware environment. The applications may range from simple data logging or signal generation ones to very advanced controllers. Taking advantage of the Simulink simulation capabilities and user-friendly hardware implementation routines, the framework significantly decreases the development time of FPGA-based applications.

A Framework for Assessing the Reusability of Hardware (Reusable Rocket Engines)

NASA Technical Reports Server (NTRS)

Childress-Thompson, Rhonda; Farrington, Philip; Thomas, Dale

2016-01-01

Within the space flight community, reusability has taken center stage as the new buzzword. In order for reusable hardware to be competitive with its expendable counterpart, two major elements must be closely scrutinized. First, recovery and refurbishment costs must be lower than the development and acquisition costs. Additionally, the reliability for reused hardware must remain the same (or nearly the same) as "first use" hardware. Therefore, it is imperative that a systematic approach be established to enhance the development of reusable systems. However, before the decision can be made on whether it is more beneficial to reuse hardware or to replace it, the parameters that are needed to deem hardware worthy of reuse must be identified. For reusable hardware to be successful, the factors that must be considered are reliability (integrity, life, number of uses), operability (maintenance, accessibility), and cost (procurement, retrieval, refurbishment). These three factors are essential to the successful implementation of reusability while enabling the ability to meet performance goals. Past and present strategies and attempts at reuse within the space industry will be examined to identify important attributes of reusability that can be used to evaluate hardware when contemplating reusable versus expendable options. This paper will examine why reuse must be stated as an initial requirement rather than included as an afterthought in the final design. Late in the process, changes in the overall objective/purpose of components typically have adverse effects that potentially negate the benefits. A methodology for assessing the viability of reusing hardware will be presented by using the Space Shuttle Main Engine (SSME) to validate the approach. Because reliability, operability, and costs are key drivers in making this critical decision, they will be used to assess requirements for reuse as applied to components of the SSME.

49 CFR 236.903 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... electrical, mechanical, hardware, or software) that is part of a system or subsystem. Configuration..., including the hardware components and software version, is documented and maintained through the life-cycle... or compensates individuals to perform the duties specified in § 236.921 (a). Executive software means...

49 CFR 236.903 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... electrical, mechanical, hardware, or software) that is part of a system or subsystem. Configuration..., including the hardware components and software version, is documented and maintained through the life-cycle... or compensates individuals to perform the duties specified in § 236.921 (a). Executive software means...

49 CFR 236.903 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... electrical, mechanical, hardware, or software) that is part of a system or subsystem. Configuration..., including the hardware components and software version, is documented and maintained through the life-cycle... or compensates individuals to perform the duties specified in § 236.921 (a). Executive software means...

49 CFR 236.903 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... electrical, mechanical, hardware, or software) that is part of a system or subsystem. Configuration..., including the hardware components and software version, is documented and maintained through the life-cycle... or compensates individuals to perform the duties specified in § 236.921 (a). Executive software means...

Independent Orbiter Assessment (IOA): Assessment of the communication and tracking subsystem, volume 1

NASA Technical Reports Server (NTRS)

Long, W. C.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed and analysis of the Communication and Tracking hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter Communication and Tracking hardware. The IOA product for the Communication and Tracking consisted of 1,108 failure mode worksheets that resulted in 298 critical items being identified. Comparison was made to the NASA baseline which consists of 697 FMEAs and 239 CIL items. The comparison determined if there were any results which had been found by IOA but were not in the NASA baseline. This comparison produced agreement on all but 407 FMEAs which caused differences in 294 CIL items. Volume 1 contains the subsystem description, assessment results, ground rules and assumptions, and some of the IOA worksheets.

Synchronization and fault-masking in redundant real-time systems

NASA Technical Reports Server (NTRS)

Krishna, C. M.; Shin, K. G.; Butler, R. W.

1983-01-01

A real time computer may fail because of massive component failures or not responding quickly enough to satisfy real time requirements. An increase in redundancy - a conventional means of improving reliability - can improve the former but can - in some cases - degrade the latter considerably due to the overhead associated with redundancy management, namely the time delay resulting from synchronization and voting/interactive consistency techniques. The implications of synchronization and voting/interactive consistency algorithms in N-modular clusters on reliability are considered. All these studies were carried out in the context of real time applications. As a demonstrative example, we have analyzed results from experiments conducted at the NASA Airlab on the Software Implemented Fault Tolerance (SIFT) computer. This analysis has indeed indicated that in most real time applications, it is better to employ hardware synchronization instead of software synchronization and not allow reconfiguration.

Evaluate the application of modal test and analysis processes to structural fault detection in MSFC - STS project elements

NASA Technical Reports Server (NTRS)

Springer, William T.

1987-01-01

The Space Transportation System (STS) is a complex and expensive flight system intended to carry unique payloads into low Earth orbit and return. A catastrophic failure, such as STS 51-L, resulted in the loss of both human life as well as expensive and unique hardware. The impact of this incident reaffirms the need to do everything possible to ensure the integrity and reliability of STS. One means of achieving this goal is to expand the number of inspection technologies available. Reported here is the evaluation of the use of modal analysis and test techniques for the purpose of assessing the structural integrity of STS components for which Marshall Space Flight Center has responsibility. This entailed reviewing existing literature and developing a low-level experimental program determine the feasibility of using this technology for structural fault detection.

Performance Characterization of Loctite (Registered Trademark) 242 and 271 Liquid Locking Compounds (LLCs) as a Secondary Locking Feature for International Space Station (ISS) Fasteners

NASA Technical Reports Server (NTRS)

Dube, Michael J.; Gamwell, Wayne R.

2011-01-01

Several International Space Station (ISS) hardware components use Loctite (and other polymer based liquid locking compounds (LLCs)) as a means of meeting the secondary (redundant) locking feature requirement for fasteners. The primary locking method is the fastener preload, with the application of the Loctite compound which when cured is intended to resist preload reduction. The reliability of these compounds has been questioned due to a number of failures during ground testing. The ISS Program Manager requested the NASA Engineering and Safety Center (NESC) to characterize and quantify sensitivities of Loctite being used as a secondary locking feature. The findings and recommendations provided in this investigation apply to the anaerobic LLCs Loctite 242 and 271. No other anaerobic LLCs were evaluated for this investigation. This document contains the findings and recommendations of the NESC investigation

Method of Testing and Predicting Failures of Electronic Mechanical Systems

NASA Technical Reports Server (NTRS)

Iverson, David L.; Patterson-Hine, Frances A.

1996-01-01

A method employing a knowledge base of human expertise comprising a reliability model analysis implemented for diagnostic routines is disclosed. The reliability analysis comprises digraph models that determine target events created by hardware failures human actions, and other factors affecting the system operation. The reliability analysis contains a wealth of human expertise information that is used to build automatic diagnostic routines and which provides a knowledge base that can be used to solve other artificial intelligence problems.

Decomposition-Based Failure Mode Identification Method for Risk-Free Design of Large Systems

NASA Technical Reports Server (NTRS)

Tumer, Irem Y.; Stone, Robert B.; Roberts, Rory A.; Clancy, Daniel (Technical Monitor)

2002-01-01

When designing products, it is crucial to assure failure and risk-free operation in the intended operating environment. Failures are typically studied and eliminated as much as possible during the early stages of design. The few failures that go undetected result in unacceptable damage and losses in high-risk applications where public safety is of concern. Published NASA and NTSB accident reports point to a variety of components identified as sources of failures in the reported cases. In previous work, data from these reports were processed and placed in matrix form for all the system components and failure modes encountered, and then manipulated using matrix methods to determine similarities between the different components and failure modes. In this paper, these matrices are represented in the form of a linear combination of failures modes, mathematically formed using Principal Components Analysis (PCA) decomposition. The PCA decomposition results in a low-dimensionality representation of all failure modes and components of interest, represented in a transformed coordinate system. Such a representation opens the way for efficient pattern analysis and prediction of failure modes with highest potential risks on the final product, rather than making decisions based on the large space of component and failure mode data. The mathematics of the proposed method are explained first using a simple example problem. The method is then applied to component failure data gathered from helicopter, accident reports to demonstrate its potential.

Real-Time Rocket/Vehicle System Integrated Health Management Laboratory For Development and Testing of Health Monitoring/Management Systems

NASA Technical Reports Server (NTRS)

Aguilar, R.

2006-01-01

Pratt & Whitney Rocketdyne has developed a real-time engine/vehicle system integrated health management laboratory, or testbed, for developing and testing health management system concepts. This laboratory simulates components of an integrated system such as the rocket engine, rocket engine controller, vehicle or test controller, as well as a health management computer on separate general purpose computers. These general purpose computers can be replaced with more realistic components such as actual electronic controllers and valve actuators for hardware-in-the-loop simulation. Various engine configurations and propellant combinations are available. Fault or failure insertion capability on-the-fly using direct memory insertion from a user console is used to test system detection and response. The laboratory is currently capable of simulating the flow-path of a single rocket engine but work is underway to include structural and multiengine simulation capability as well as a dedicated data acquisition system. The ultimate goal is to simulate as accurately and realistically as possible the environment in which the health management system will operate including noise, dynamic response of the engine/engine controller, sensor time delays, and asynchronous operation of the various components. The rationale for the laboratory is also discussed including limited alternatives for demonstrating the effectiveness and safety of a flight system.

Compiler-assisted multiple instruction rollback recovery using a read buffer

NASA Technical Reports Server (NTRS)

Alewine, Neal J.; Chen, Shyh-Kwei; Fuchs, W. Kent; Hwu, Wen-Mei W.

1995-01-01

Multiple instruction rollback (MIR) is a technique that has been implemented in mainframe computers to provide rapid recovery from transient processor failures. Hardware-based MIR designs eliminate rollback data hazards by providing data redundancy implemented in hardware. Compiler-based MIR designs have also been developed which remove rollback data hazards directly with data-flow transformations. This paper describes compiler-assisted techniques to achieve multiple instruction rollback recovery. We observe that some data hazards resulting from instruction rollback can be resolved efficiently by providing an operand read buffer while others are resolved more efficiently with compiler transformations. The compiler-assisted scheme presented consists of hardware that is less complex than shadow files, history files, history buffers, or delayed write buffers, while experimental evaluation indicates performance improvement over compiler-based schemes.

Using failure mode and effects analysis to plan implementation of smart i.v. pump technology.

PubMed

Wetterneck, Tosha B; Skibinski, Kathleen A; Roberts, Tanita L; Kleppin, Susan M; Schroeder, Mark E; Enloe, Myra; Rough, Steven S; Hundt, Ann Schoofs; Carayon, Pascale

2006-08-15

Failure mode and effects analysis (FMEA) was used to evaluate a smart i.v. pump as it was implemented into a redesigned medication-use process. A multidisciplinary team conducted a FMEA to guide the implementation of a smart i.v. pump that was designed to prevent pump programming errors. The smart i.v. pump was equipped with a dose-error reduction system that included a pre-defined drug library in which dosage limits were set for each medication. Monitoring for potential failures and errors occurred for three months postimplementation of FMEA. Specific measures were used to determine the success of the actions that were implemented as a result of the FMEA. The FMEA process at the hospital identified key failure modes in the medication process with the use of the old and new pumps, and actions were taken to avoid errors and adverse events. I.V. pump software and hardware design changes were also recommended. Thirteen of the 18 failure modes reported in practice after pump implementation had been identified by the team. A beneficial outcome of FMEA was the development of a multidisciplinary team that provided the infrastructure for safe technology implementation and effective event investigation after implementation. With the continual updating of i.v. pump software and hardware after implementation, FMEA can be an important starting place for safe technology choice and implementation and can produce site experts to follow technology and process changes over time. FMEA was useful in identifying potential problems in the medication-use process with the implementation of new smart i.v. pumps. Monitoring for system failures and errors after implementation remains necessary.

Resilience Design Patterns - A Structured Approach to Resilience at Extreme Scale (version 1.1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hukerikar, Saurabh; Engelmann, Christian

Reliability is a serious concern for future extreme-scale high-performance computing (HPC) systems. Projections based on the current generation of HPC systems and technology roadmaps suggest the prevalence of very high fault rates in future systems. The errors resulting from these faults will propagate and generate various kinds of failures, which may result in outcomes ranging from result corruptions to catastrophic application crashes. Therefore the resilience challenge for extreme-scale HPC systems requires management of various hardware and software technologies that are capable of handling a broad set of fault models at accelerated fault rates. Also, due to practical limits on powermore » consumption in HPC systems future systems are likely to embrace innovative architectures, increasing the levels of hardware and software complexities. As a result the techniques that seek to improve resilience must navigate the complex trade-off space between resilience and the overheads to power consumption and performance. While the HPC community has developed various resilience solutions, application-level techniques as well as system-based solutions, the solution space of HPC resilience techniques remains fragmented. There are no formal methods and metrics to investigate and evaluate resilience holistically in HPC systems that consider impact scope, handling coverage, and performance & power efficiency across the system stack. Additionally, few of the current approaches are portable to newer architectures and software environments that will be deployed on future systems. In this document, we develop a structured approach to the management of HPC resilience using the concept of resilience-based design patterns. A design pattern is a general repeatable solution to a commonly occurring problem. We identify the commonly occurring problems and solutions used to deal with faults, errors and failures in HPC systems. Each established solution is described in the form of a pattern that addresses concrete problems in the design of resilient systems. The complete catalog of resilience design patterns provides designers with reusable design elements. We also define a framework that enhances a designer's understanding of the important constraints and opportunities for the design patterns to be implemented and deployed at various layers of the system stack. This design framework may be used to establish mechanisms and interfaces to coordinate flexible fault management across hardware and software components. The framework also supports optimization of the cost-benefit trade-offs among performance, resilience, and power consumption. The overall goal of this work is to enable a systematic methodology for the design and evaluation of resilience technologies in extreme-scale HPC systems that keep scientific applications running to a correct solution in a timely and cost-efficient manner in spite of frequent faults, errors, and failures of various types.« less

45 CFR 307.5 - Mandatory computerized support enforcement systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... hardware, operational system software, and electronic linkages with the separate components of an... plans to use and how they will interface with the base system; (3) Provide documentation that the... and for operating costs including hardware, operational software and applications software of a...

45 CFR 307.5 - Mandatory computerized support enforcement systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... hardware, operational system software, and electronic linkages with the separate components of an... plans to use and how they will interface with the base system; (3) Provide documentation that the... and for operating costs including hardware, operational software and applications software of a...

45 CFR 307.5 - Mandatory computerized support enforcement systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... hardware, operational system software, and electronic linkages with the separate components of an... plans to use and how they will interface with the base system; (3) Provide documentation that the... and for operating costs including hardware, operational software and applications software of a...

Evaluating the Applicability of Heritage Flight Hardware in Orion Environmental Control and Life Support Systems

NASA Technical Reports Server (NTRS)

Cross, Cynthia D.; Lewis, John F.; Barido, Richard A.; Carrasquillo, Robyn; Rains, George E.

2011-01-01

Recent changes in the overall NASA vision has resulted in further cost and schedule challenges for the Orion program. As a result, additional scrutiny has been focused on the use of new developments for hardware in the environmental control and life support systems. This paper will examine the Orion architecture as it is envisioned to support missions to the International Space Station and future exploration missions and determine what if any functions can be satisfied through the use of existing, heritage hardware designs. An initial evaluation of each component is included and where a heritage component was deemed likely further details are examined. Key technical parameters, mass, volume and vibration loads are a few of the specific items that are evaluated. Where heritage hardware has been identified that may be substituted in the Orion architecture a discussion of key requirement changes that may need to be made as well as recommendation to further evaluate applicability are noted.

Fatigue failure of metal components as a factor in civil aircraft accidents

NASA Technical Reports Server (NTRS)

Holshouser, W. L.; Mayner, R. D.

1972-01-01

A review of records maintained by the National Transportation Safety Board showed that 16,054 civil aviation accidents occurred in the United States during the 3-year period ending December 31, 1969. Material failure was an important factor in the cause of 942 of these accidents. Fatigue was identified as the mode of the material failures associated with the cause of 155 accidents and in many other accidents the records indicated that fatigue failures might have been involved. There were 27 fatal accidents and 157 fatalities in accidents in which fatigue failures of metal components were definitely identified. Fatigue failures associated with accidents occurred most frequently in landing-gear components, followed in order by powerplant, propeller, and structural components in fixed-wing aircraft and tail-rotor and main-rotor components in rotorcraft. In a study of 230 laboratory reports on failed components associated with the cause of accidents, fatigue was identified as the mode of failure in more than 60 percent of the failed components. The most frequently identified cause of fatigue, as well as most other types of material failures, was improper maintenance (including inadequate inspection). Fabrication defects, design deficiencies, defective material, and abnormal service damage also caused many fatigue failures. Four case histories of major accidents are included in the paper as illustrations of some of the factors invovled in fatigue failures of aircraft components.

Oxygen Generation System Laptop Bus Controller Flight Software

NASA Technical Reports Server (NTRS)

Rowe, Chad; Panter, Donna

2009-01-01

The Oxygen Generation System Laptop Bus Controller Flight Software was developed to allow the International Space Station (ISS) program to activate specific components of the Oxygen Generation System (OGS) to perform a checkout of key hardware operation in a microgravity environment, as well as to perform preventative maintenance operations of system valves during a long period of what would otherwise be hardware dormancy. The software provides direct connectivity to the OGS Firmware Controller with pre-programmed tasks operated by on-orbit astronauts to exercise OGS valves and motors. The software is used to manipulate the pump, separator, and valves to alleviate the concerns of hardware problems due to long-term inactivity and to allow for operational verification of microgravity-sensitive components early enough so that, if problems are found, they can be addressed before the hardware is required for operation on-orbit. The decision was made to use existing on-orbit IBM ThinkPad A31p laptops and MIL-STD-1553B interface cards as the hardware configuration. The software at the time of this reporting was developed and tested for use under the Windows 2000 Professional operating system to ensure compatibility with the existing on-orbit computer systems.

Logic Design Pathology and Space Flight Electronics

NASA Technical Reports Server (NTRS)

Katz, Richard B.; Barto, Rod L.; Erickson, Ken

1999-01-01

This paper presents a look at logic design from early in the US Space Program and examines faults in recent logic designs. Most examples are based on flight hardware failures and analysis of new tools and techniques. The paper is presented in viewgraph form.

The implementation and use of Ada on distributed systems with reliability requirements

NASA Technical Reports Server (NTRS)

Reynolds, P. F.; Knight, J. C.; Urquhart, J. I. A.

1983-01-01

The issues involved in the use of the programming language Ada on distributed systems are discussed. The effects of Ada programs on hardware failures such as loss of a processor are emphasized. It is shown that many Ada language elements are not well suited to this environment. Processor failure can easily lead to difficulties on those processors which remain. As an example, the calling task in a rendezvous may be suspended forever if the processor executing the serving task fails. A mechanism for detecting failure is proposed and changes to the Ada run time support system are suggested which avoid most of the difficulties. Ada program structures are defined which allow programs to reconfigure and continue to provide service following processor failure.

ACIS Door Failure Investigation and Mitigation Procedures

NASA Technical Reports Server (NTRS)

Podgorski, William A.; Tice, Neil W.; Plucinsky, Paul P.

2000-01-01

NASA's Chandra X-ray Observatory (formerly AXAF) was launched on July 23, 1999 and is currently in orbit performing scientific studies. Chandra is the third of NASA's Great Observatories to be launched, following the Hubble Space Telescope and the Compton Gamma Ray Observatory. One of four primary science instruments on Chandra, and one of only two focal plane instruments, is the Advanced CCD Imaging Spectrometer, or ACIS. The ACIS focal plane and Optical Blocking Filter (OBF) must be launched under vacuum, so a tightly sealed, functioning door and venting subsystem were implemented. The door was opened two and one-half weeks after launch (after most out-gassing of composite materials) and allowed X-rays to be imaged by the ACIS CCD's in the focal plane. A failure of this door to open on-orbit would have eliminated all ACIS capabilities, severely degrading mission science. During the final pre-flight thermal-vacuum test of the fully integrated Chandra Observatory at TRW, the ACIS door failed to open when commanded to do so. This paper describes the efforts, under considerable time pressure, by NASA, its contractors and outside review teams to investigate the failure and to develop modified hardware and procedures which would correct the problem. Of interest is the fact that the root cause of the test failure was never clearly identified despite massive effort. We ultimately focussed on hardware and procedures designed to mitigate the effects of potential, but unproven, failure modes. We describe a frequent real-world engineering situation in which one must proceed on the best basis possible in the absence of the complete set of facts.

Estimation procedures to measure and monitor failure rates of components during thermal-vacuum testing

NASA Technical Reports Server (NTRS)

Williams, R. E.; Kruger, R.

1980-01-01

Estimation procedures are described for measuring component failure rates, for comparing the failure rates of two different groups of components, and for formulating confidence intervals for testing hypotheses (based on failure rates) that the two groups perform similarly or differently. Appendix A contains an example of an analysis in which these methods are applied to investigate the characteristics of two groups of spacecraft components. The estimation procedures are adaptable to system level testing and to monitoring failure characteristics in orbit.

Digital video timing analyzer for the evaluation of PC-based real-time simulation systems

NASA Astrophysics Data System (ADS)

Jones, Shawn R.; Crosby, Jay L.; Terry, John E., Jr.

2009-05-01

Due to the rapid acceleration in technology and the drop in costs, the use of commercial off-the-shelf (COTS) PC-based hardware and software components for digital and hardware-in-the-loop (HWIL) simulations has increased. However, the increase in PC-based components creates new challenges for HWIL test facilities such as cost-effective hardware and software selection, system configuration and integration, performance testing, and simulation verification/validation. This paper will discuss how the Digital Video Timing Analyzer (DiViTA) installed in the Aviation and Missile Research, Development and Engineering Center (AMRDEC) provides quantitative characterization data for PC-based real-time scene generation systems. An overview of the DiViTA is provided followed by details on measurement techniques, applications, and real-world examples of system benefits.

How to Extend the Capabilities of Space Systems for Long Duration Space Exploration Systems

NASA Technical Reports Server (NTRS)

Marzwell, Neville I.; Waterman, Robert D.; KrishnaKumar, Kalmanje; Waterman, Susan J.

2005-01-01

For sustainable Exploration Missions the need exists to assemble systems-of-systems in space, on the Moon or on other planetary surfaces. To fulfill this need new and innovative system architecture is needed that can be satisfied with the present lift capability of existing rocket technology without the added cost of developing a new heavy lift vehicle. To enable ultra-long life missions with minimum redundancy and lighter mass the need exists to develop system soft,i,are and hardware reconfigurability, which enables increasing functionality and multiple use of launched assets while at the same time overcoming any components failures. Also the need exists to develop the ability to dynamically demate and reassemble individual system elements during a mission in order to work around failed hardware or changed mission requirements. Therefore to meet the goals of Space Exploration Missions in hiteroperability and Reconfigurability, many challenges must be addressed to transform the traditional static avionics architecture into architecture with dynamic capabilities. The objective of this paper is to introduce concepts associated with reconfigurable computer systems; review the various needs and challenges associated with reconfigurable avionics space systems; provide an operational example that illustrates the needs applicable to either the Crew Exploration Vehicle or a collection of "Habot like" mobile surface elements; summarize the approaches that address key challenges to acceptance of a Flexible, Intelligent, Modular and Affordable reconfigurable avionics space system.

Cutting More than Metal: Breaking the Development Cycle

NASA Technical Reports Server (NTRS)

Singer, Chris

2014-01-01

New technology is changing the way we do business at NASA. The ability to use these new tools is made possible by a learning culture able to embrace innovation, flexibility, and prudent risk tolerance, while retaining the hard-won lessons learned of other successes and failures. Technologies such as 3-D manufacturing and structured light scanning are re-shaping the entire product life cycle, from design and analysis, through production, verification, logistics and operations. New fabrication techniques, verification techniques, integrated analysis, and models that follow the hardware from initial concept through operation are reducing the cost and time of building space hardware. Using these technologies to be more efficient, reliable and affordable requires we bring them to a level safe for NASA systems, maintain appropriate rigor in testing and acceptance, and transition new technology. Maximizing these technologies also requires cultural acceptance and understanding and balancing rules with creativity. Evolved systems engineering processes at NASA are increasingly more flexible than they have been in the past, enabling the implementation of new techniques and approaches. This paper provides an overview of NASA Marshall Space Flight Center's new approach to development, as well as examples of how that approach has been incorporated into NASA's Space Launch System (SLS) Program, which counts among its key tenants - safety, affordability, and sustainability. One of the 3D technologies that will be discussed in this paper is the design and testing of various rocket engine components.

AdaNET Dynamic Software Inventory (DSI) prototype component acquisition plan

NASA Technical Reports Server (NTRS)

Hanley, Lionel

1989-01-01

A component acquisition plan contains the information needed to evaluate, select, and acquire software and hardware components necessary for successful completion of the AdaNET Dynamic Software Inventory (DSI) Management System Prototype. This plan will evolve and be applicable to all phases of the DSI prototype development. Resources, budgets, schedules, and organizations related to component acquisition activities are provided. A purpose and description of a software or hardware component which is to be acquired are presented. Since this is a plan for acquisition of all components, this section is not applicable. The procurement activities and events conducted by the acquirer are described and who is responsible is identified, where the activity will be performed, and when the activities will occur for each planned procurement. Acquisition requirements describe the specific requirements and standards to be followed during component acquisition. The activities which will take place during component acquisition are described. A list of abbreviations and acronyms, and a glossary are contained.

Early Comparative Outcomes of Carbon Fiber Reinforced Polymer Plate in the Fixation of Distal Femur Fractures.

PubMed

Mitchell, Phillip M; Lee, Adam K; Collinge, Cory A; Ziran, Bruce H; Hartley, Kate G; Jahangir, A Alex

2018-05-16

To evaluate the early clinical results of distal femur fractures treated with carbon fiber reinforced - polyetheretherketone (CFR-PEEK) plates compared to stainless steel (SS) lateral locking plates. Retrospective comparative cohort study SETTING:: ACS Level I trauma center. Twenty-two patients (11 SS, 11 CFR-PEEK) with closed distal femur fractures treated by a single surgeon over a 6-year period. Nonunion, hardware failure, reoperation, time to full weight bearing, and time ` union were assessed. The CFR-PEEK cohort was on average older (71 vs. 57 years, p=0.03) and more likely to have diabetes (p=0.02). Nonunion was diagnosed in 4/11 (36%) patients in the SS group and 1/11 (9%) patients in the CFR-PEEK group (p=0.12). Hardware failure occurred in two SS patients (18%) compared to none in the CFR-PEEK group (p=0.14). Time to full weight bearing was similar between groups occurring at 9.9 weeks and 12.4 weeks in the CFR-PEEK and SS groups, respectively (p=0.23). Time to radiographic union averaged 12.4 weeks in the SS group and 18.7 weeks in the CFR-PEEK group (p=0.26). There were 4 reoperations in the SS group and one in the CFR-PEEK group (p=0.12). CFR-PEEK plates show encouraging short-term results in the treatment of distal femur fractures with a comparable nonunion, reoperation, and hardware failure rates to those treated with SS plates. This data suggests CFR-PEEK plates may be a viable alternative to SS plates in fixation of these fractures. Level III.

Knowledge representation and user interface concepts to support mixed-initiative diagnosis

NASA Technical Reports Server (NTRS)

Sobelman, Beverly H.; Holtzblatt, Lester J.

1989-01-01

The Remote Maintenance Monitoring System (RMMS) provides automated support for the maintenance and repair of ModComp computer systems used in the Launch Processing System (LPS) at Kennedy Space Center. RMMS supports manual and automated diagnosis of intermittent hardware failures, providing an efficient means for accessing and analyzing the data generated by catastrophic failure recovery procedures. This paper describes the design and functionality of the user interface for interactive analysis of memory dump data, relating it to the underlying declarative representation of memory dumps.

Failure Analysis of Space Shuttle Orbiter Valve Poppet

NASA Technical Reports Server (NTRS)

Russell, Rick

2010-01-01

The poppet failed during STS-126 due to fatigue cracking that most likely was initiated during MDC ground-testing. This failure ultimately led to the discovery that the cracking problem was a generic issue effecting numerous poppets throughout the Shuttle program's history. This presentation has focused on the laboratory analysis of the failed hardware, but this analysis was only one aspect of a comprehensive failure investigation. One critical aspect of the overall investigation was modeling of the fluid flow through this valve to determine the possible sources of cyclic loading. This work has led to the conclusion that the poppets are failing due to flow-induced vibration.

Design of Critical Components

NASA Technical Reports Server (NTRS)

Hendricks, Robert C.; Zaretsky, Erwin V.

2001-01-01

Critical component design is based on minimizing product failures that results in loss of life. Potential catastrophic failures are reduced to secondary failures where components removed for cause or operating time in the system. Issues of liability and cost of component removal become of paramount importance. Deterministic design with factors of safety and probabilistic design address but lack the essential characteristics for the design of critical components. In deterministic design and fabrication there are heuristic rules and safety factors developed over time for large sets of structural/material components. These factors did not come without cost. Many designs failed and many rules (codes) have standing committees to oversee their proper usage and enforcement. In probabilistic design, not only are failures a given, the failures are calculated; an element of risk is assumed based on empirical failure data for large classes of component operations. Failure of a class of components can be predicted, yet one can not predict when a specific component will fail. The analogy is to the life insurance industry where very careful statistics are book-kept on classes of individuals. For a specific class, life span can be predicted within statistical limits, yet life-span of a specific element of that class can not be predicted.

High performance VLSI telemetry data systems

NASA Technical Reports Server (NTRS)

Chesney, J.; Speciale, N.; Horner, W.; Sabia, S.

1990-01-01

NASA's deployment of major space complexes such as Space Station Freedom (SSF) and the Earth Observing System (EOS) will demand increased functionality and performance from ground based telemetry acquisition systems well above current system capabilities. Adaptation of space telemetry data transport and processing standards such as those specified by the Consultative Committee for Space Data Systems (CCSDS) standards and those required for commercial ground distribution of telemetry data, will drive these functional and performance requirements. In addition, budget limitations will force the requirement for higher modularity, flexibility, and interchangeability at lower cost in new ground telemetry data system elements. At NASA's Goddard Space Flight Center (GSFC), the design and development of generic ground telemetry data system elements, over the last five years, has resulted in significant solutions to these problems. This solution, referred to as the functional components approach includes both hardware and software components ready for end user application. The hardware functional components consist of modern data flow architectures utilizing Application Specific Integrated Circuits (ASIC's) developed specifically to support NASA's telemetry data systems needs and designed to meet a range of data rate requirements up to 300 Mbps. Real-time operating system software components support both embedded local software intelligence, and overall system control, status, processing, and interface requirements. These components, hardware and software, form the superstructure upon which project specific elements are added to complete a telemetry ground data system installation. This paper describes the functional components approach, some specific component examples, and a project example of the evolution from VLSI component, to basic board level functional component, to integrated telemetry data system.

Use of Probabilistic Engineering Methods in the Detailed Design and Development Phases of the NASA Ares Launch Vehicle

NASA Technical Reports Server (NTRS)

Fayssal, Safie; Weldon, Danny

2008-01-01

The United States National Aeronautics and Space Administration (NASA) is in the midst of a space exploration program called Constellation to send crew and cargo to the international Space Station, to the moon, and beyond. As part of the Constellation program, a new launch vehicle, Ares I, is being developed by NASA Marshall Space Flight Center. Designing a launch vehicle with high reliability and increased safety requires a significant effort in understanding design variability and design uncertainty at the various levels of the design (system, element, subsystem, component, etc.) and throughout the various design phases (conceptual, preliminary design, etc.). In a previous paper [1] we discussed a probabilistic functional failure analysis approach intended mainly to support system requirements definition, system design, and element design during the early design phases. This paper provides an overview of the application of probabilistic engineering methods to support the detailed subsystem/component design and development as part of the "Design for Reliability and Safety" approach for the new Ares I Launch Vehicle. Specifically, the paper discusses probabilistic engineering design analysis cases that had major impact on the design and manufacturing of the Space Shuttle hardware. The cases represent important lessons learned from the Space Shuttle Program and clearly demonstrate the significance of probabilistic engineering analysis in better understanding design deficiencies and identifying potential design improvement for Ares I. The paper also discusses the probabilistic functional failure analysis approach applied during the early design phases of Ares I and the forward plans for probabilistic design analysis in the detailed design and development phases.

An Alternative Approach to Human Servicing of Crewed Earth Orbiting Spacecraft

NASA Technical Reports Server (NTRS)

Mularski, John R.; Alpert, Brian K.

2017-01-01

As crewed spacecraft have grown larger and more complex, they have come to rely on spacewalks, or Extravehicular Activities (EVA), for mission success and crew safety. Typically, these spacecraft maintain all of the hardware and trained personnel needed to perform an EVA on-board at all times. Maintaining this capability requires volume and up-mass for storage of EVA hardware, crew time for ground and on-orbit training, and on-orbit maintenance of EVA hardware. This paper proposes an alternative methodology, utilizing launch on-need hardware and crew to provide EVA capability for space stations in Earth orbit after assembly complete, in the same way that one would call a repairman to fix something at their home. This approach would reduce ground training requirements, save Intravehicular Activity (IVA) crew time in the form of EVA hardware maintenance and on-orbit training, and lead to more efficient EVAs because they would be performed by specialists with detailed knowledge and training stemming from their direct involvement in the development of the EVA. The on-orbit crew would then be available to focus on the immediate response to the failure as well as the day-to-day operations of the spacecraft and payloads. This paper will look at how current unplanned EVAs are conducted, including the time required for preparation, and offer alternatives for future spacecraft. As this methodology relies on the on-time and on-need launch of spacecraft, any space station that utilized this approach would need a robust transportation system including more than one launch vehicle capable of carrying crew. In addition, the fault tolerance of the space station would be an important consideration in how much time was available for EVA preparation after the failure. Each future program would have to weigh the risk of on-time launch against the increase in available crew time for the main objective of the spacecraft.

An Alternative Approach to Human Servicing of Manned Earth Orbiting Spacecraft

NASA Technical Reports Server (NTRS)

Mularski, John; Alpert, Brian

2011-01-01

As manned spacecraft have grown larger and more complex, they have come to rely on spacewalks or Extravehicular Activities (EVA) for both mission success and crew safety. Typically these spacecraft maintain all of the hardware and trained personnel needed to perform an EVA on-board at all times. Maintaining this capability requires volume and up-mass for storage of EVA hardware, crew time for ground and on-orbit training, and on-orbit maintenance of EVA hardware . This paper proposes an alternative methodology to utilize launch-on-need hardware and crew to provide EVA capability for space stations in Earth orbit after assembly complete, in the same way that most people would call a repairman to fix something at their home. This approach would not only reduce ground training requirements and save Intravehicular Activity (IVA) crew time in the form of EVA hardware maintenance and on-orbit training, but would also lead to more efficient EVAs because they would be performed by specialists with detailed knowledge and training stemming from their direct involvement in the development of the EVA. The on-orbit crew would then be available to focus on the immediate response to the failure as well as the day-to-day operations of the spacecraft and payloads. This paper will look at how current ISS unplanned EVAs are conducted, including the time required for preparation, and offer alternatives for future spacecraft utilizing lessons learned from ISS. As this methodology relies entirely on the on-time and on-need launch of spacecraft, any space station that utilized this approach would need a robust transportation system including more than one launch vehicle capable of carrying crew. In addition the fault tolerance of the space station would be an important consideration in how much time was available for EVA preparation after the failure. Each future program would have to weigh the risk of on-time launch against the increase in available crew time for the main objective of the spacecraft.

Towards improved hardware component attenuation correction in PET/MR hybrid imaging

NASA Astrophysics Data System (ADS)

Paulus, D. H.; Tellmann, L.; Quick, H. H.

2013-11-01

In positron emission tomography/computed tomography (PET/CT) hybrid imaging attenuation correction (AC) of the patient tissue and patient table is performed by converting the CT-based Hounsfield units (HU) to linear attenuation coefficients (LAC) of PET. When applied to the new field of hardware component AC in PET/magnetic resonance (MR) hybrid imaging, this conversion method may result in local overcorrection of PET activity values. The aim of this study thus was to optimize the conversion parameters for CT-based AC of hardware components in PET/MR. Systematic evaluation and optimization of the HU to LAC conversion parameters has been performed for the hardware component attenuation map (µ-map) of a flexible radiofrequency (RF) coil used in PET/MR imaging. Furthermore, spatial misregistration of this RF coil to its µ-map was simulated by shifting the µ-map in different directions and the effect on PET quantification was evaluated. Measurements of a PET NEMA standard emission phantom were performed on an integrated hybrid PET/MR system. Various CT parameters were used to calculate different µ-maps for the flexible RF coil and to evaluate the impact on the PET activity concentration. A 511 keV transmission scan of the local RF coil was used as standard of reference to adapt the slope of the conversion from HUs to LACs at 511 keV. The average underestimation of the PET activity concentration due to the non-attenuation corrected RF coil in place was calculated to be 5.0% in the overall phantom. When considering attenuation only in the upper volume of the phantom, the average difference to the reference scan without RF coil is 11.0%. When the PET/CT conversion is applied, an average overestimation of 3.1% (without extended CT scale) and 4.2% (with extended CT scale) is observed in the top volume of the NEMA phantom. Using the adapted conversion resulting from this study, the deviation in the top volume of the phantom is reduced to -0.5% and shows the lowest standard deviation inside the phantom in comparison to all other conversions. Simulation of a µ-map misregistration shows acceptable results for shifts below 5 mm for the flexible surface RF coil. The adapted conversion from HUs to LAC at 511 keV within this study can improve hardware component AC in PET/MR hybrid imaging as shown for a flexible RF surface coil. Furthermore, these results have a direct impact on the improvement of the hardware component AC of the examined flexible RF coil in conjunction with position determination.

Toward Patient Specific Long Lasting Metallic Implants for Mandibular Segmental Defects

NASA Astrophysics Data System (ADS)

Shayesteh Moghaddam, Narges

Mandibular defects may result from tumor resection, trauma, or inflammation. The goals of mandibular reconstruction surgeries are to restore mandible function and aesthetics. To this end, surgeons use a combination of bone grafts and metallic implants. These implants have drastically different mechanical properties than the surrounding bone. As a result, the stress distribution in the mandible changes after surgery. The long-term abnormal stress/strain distribution may lead to either graft failure due to bone resorption as a result of stress shielding, or hardware failure due to stress concentrations. During the healing period of six to nine months it is important that complete immobilization, bringing mandibular micro-motion down to the level of 200-500 mum during chewing, is achieved. After this period it is desired that bone undergo normal stress for long-term success of the treatment. Although current high stiffness fixation hardware accomplishes this immobilization during the healing period, the hardware continues to alter the normal stress-strain trajectory seen during chewing once the engrafted bone heals. Over the long-term, the immobilized and stress-shielded engrafted bone tends to resorb. On the other hand, hardware fracturing or/and screw loosening is observed as the stress is concentrated at certain locations on the hardware. Equally as important is the permanent loss of chewing power due to the altered stress-strain relationships. The first stage of this research is to study the problems encountered following a mandibular segmental defect reconstructive surgery. To this end, we constructed a finite element model of a healthy mandible, which includes cortical and cancellous bone, teeth (enamel and dentin components), and the periodontal ligament. Using this model, we studied a healthy adult mandible under maximum molar bite force for stress, strain, displacement, and reaction force distribution. For mandibular segmental defect reconstruction the current standard of care consists of the use of Surgical Grade 5 titanium also known as Ti-6Al-4V hardware and either a single or double fibula barrel vascularized bone graft. We expanded our model to simulate the effects of this surgery. The expanded model includes both single and double barrel fibular bone graft repair of a right M1-M3 containing section of the mandible, Ti-6Al-4V fixation hardware and screws. We found that the stiffness mismatch between the fixation hardware and the bone causes stress shielding on the host mandible and the bone graft, and stress concentration at the fixation hardware and screws. The simulations results show that while a double-barrel graft is preferred, in the long-term it does not create the optimal outcome due to the abnormal stress pattern. To improve the long-term outcome with metallic implants it is essential to recreate the normal stress pattern. To achieve this outcome we investigated the use of porous nitinol as a substitute for the currently used titanium hardware. While NiTi already has a lower stiffness than titanium, it is possible to add porosity to further reduce the stiffness to be closer to that of cortical bone. The ultimate goal is to create fixation hardware that has sufficient stiffness for immobilization while recreating the normal stress pattern in the bone. Using a finite element model of devices fabricated from Surgical Grade 5 titanium and NiTi, we have found that stiffness-tuned NiTi hardware with conventional geometries should result in recreation of normal stress-strain trajectories and better treatment outcome. Finally, to further improve the outcome, we suggest the use of a two-stage mechanism Bone Bandaid which supports both the immobilization/healing and regenerative phases of mandibular segmental defect treatment. This device is made of two materials. The stiff Ti-6Al-4V portion provides the support during the healing period and is disengaged afterwards. The second material is a NiTi wire-frame to facilitate normal stress distribution after the initial healing period. The titanium part of this fixation hardware is released following radiological verification that the surgical osteotomies have healed. The release procedure is performed under local anesthetic via a microsurgical tool. With the titanium fixation hardware no longer functional, the NiTi webbing would act as a superstructure, like a skin, to the underlying grafted cortical bone. This device facilitates stress transduction through the normal stress-strain trajectories, allows restoration of power, drives cortical bone remodeling and strengthening, provides long-term strength, and a good bone bed for dental implants. If bone chips are used, instead of single or double bone graft, the webbing is more likely to support the bone chips while they are being incorporated with the mandible. We have performed computer simulation to investigate the two stages of the operation of the device. Our FEA results indicate that the Bone Bandaid supports both the immobilization needed during healing and the distribution of stress through the engrafted bone once it has healed. (Abstract shortened by ProQuest.).

Bistatic radar sea state monitoring system design

NASA Technical Reports Server (NTRS)

Ruck, G. T.; Krichbaum, C. K.; Everly, J. O.

1975-01-01

Remote measurement of the two-dimensional surface wave height spectrum of the ocean by the use of bistatic radar techniques was examined. Potential feasibility and experimental verification by field experiment are suggested. The required experimental hardware is defined along with the designing, assembling, and testing of several required experimental hardware components.

21 CFR 892.2050 - Picture archiving and communications system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... processing of medical images. Its hardware components may include workstations, digitizers, communications... hardcopy devices. The software components may provide functions for performing operations related to image...

21 CFR 892.2050 - Picture archiving and communications system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... processing of medical images. Its hardware components may include workstations, digitizers, communications... hardcopy devices. The software components may provide functions for performing operations related to image...

21 CFR 892.2050 - Picture archiving and communications system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... processing of medical images. Its hardware components may include workstations, digitizers, communications... hardcopy devices. The software components may provide functions for performing operations related to image...

21 CFR 892.2050 - Picture archiving and communications system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... processing of medical images. Its hardware components may include workstations, digitizers, communications... hardcopy devices. The software components may provide functions for performing operations related to image...

Multiple IMU system development, volume 1

NASA Technical Reports Server (NTRS)

Landey, M.; Mckern, R.

1974-01-01

A redundant gimballed inertial system is described. System requirements and mechanization methods are defined and hardware and software development is described. Failure detection and isolation algorithms are presented and technology achievements described. Application of the system as a test tool for shuttle avionics concepts is outlined.

45 CFR 95.610 - Submission of advance planning documents.

Code of Federal Regulations, 2011 CFR

2011-10-01

... system failure and disaster recovery/business continuity procedures available or to be implemented; and... generally applies to large statewide system developments and/or major hardware acquisitions. States with large, independent counties requesting funding at the regular match rate for county systems are strongly...

PV Reliability -- Where We've Been and Where We're Going

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurtz, Sarah

2017-04-27

The photovoltaic (PV) industry has demonstrated impressive progress toward deploying hardware with excellent quality. As module prices drop and designs are squeezed to reduce cost of materials and processing, how will this affect the failures that are seen in the field?

Investigating an API for resilient exascale computing.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stearley, Jon R.; Tomkins, James; VanDyke, John P.

2013-05-01

Increased HPC capability comes with increased complexity, part counts, and fault occurrences. In- creasing the resilience of systems and applications to faults is a critical requirement facing the viability of exascale systems, as the overhead of traditional checkpoint/restart is projected to outweigh its bene ts due to fault rates outpacing I/O bandwidths. As faults occur and propagate throughout hardware and software layers, pervasive noti cation and handling mechanisms are necessary. This report describes an initial investigation of fault types and programming interfaces to mitigate them. Proof-of-concept APIs are presented for the frequent and important cases of memory errors and nodemore » failures, and a strategy proposed for lesystem failures. These involve changes to the operating system, runtime, I/O library, and application layers. While a single API for fault handling among hardware and OS and application system-wide remains elusive, the e ort increased our understanding of both the mountainous challenges and the promising trailheads. 3« less

GROVER: An autonomous vehicle for ice sheet research

NASA Astrophysics Data System (ADS)

Trisca, G. O.; Robertson, M. E.; Marshall, H.; Koenig, L.; Comberiate, M. A.

2013-12-01

The Goddard Remotely Operated Vehicle for Exploration and Research or Greenland Rover (GROVER) is a science enabling autonomous robot specifically designed to carry a low-power, large bandwidth radar for snow accumulation mapping over the Greenland Ice Sheet. This new and evolving technology enables reduced cost and increased safety for polar research. GROVER was field tested at Summit, Greenland in May 2013. The robot traveled over 30 km and was controlled both by line of sight wireless and completely autonomously with commands and telemetry via the Iridium Satellite Network, from Summit as well as remotely from Boise, Idaho. Here we describe GROVER's unique abilities and design. The software stack features a modular design that can be adapted for any application that requires autonomous behavior, reliable communications using different technologies and low level control of peripherals. The modules are built to communicate using the publisher-subscriber design pattern to maximize data-reuse and allow for graceful failures at the software level, along with the ability to be loaded or unloaded on-the-fly, enabling the software to adopt different behaviors based on power constraints or specific processing needs. These modules can also be loaded or unloaded remotely for servicing and telemetry can be configured to contain any kind of information being generated by the sensors or scientific instruments. The hardware design protects the electronic components and the control system can change functional parameters based on sensor input. Power failure modes built into the hardware prevent the vehicle from running out of energy permanently by monitoring voltage levels and triggering software reboots when the levels match pre-established conditions. This guarantees that the control software will be operational as soon as there is enough charge to sustain it, giving the vehicle increased longevity in case of a temporary power loss. GROVER demonstrates that autonomous rovers can be a revolutionary tool for data collection, and that both the technology and the software are available and ready to be implemented to create scientific data collection platforms.

Microgravity Manufacturing Via Fused Deposition

NASA Technical Reports Server (NTRS)

Cooper, K. G.; Griffin, M. R.

2003-01-01

Manufacturing polymer hardware during space flight is currently outside the state of the art. A process called fused deposition modeling (FDM) can make this approach a reality by producing net-shaped components of polymer materials directly from a CAE model. FDM is a rapid prototyping process developed by Stratasys, Inc.. which deposits a fine line of semi-molten polymer onto a substrate while moving via computer control to form the cross-sectional shape of the part it is building. The build platen is then lowered and the process is repeated, building a component directly layer by layer. This method enables direct net-shaped production of polymer components directly from a computer file. The layered manufacturing process allows for the manufacture of complex shapes and internal cavities otherwise impossible to machine. This task demonstrated the benefits of the FDM technique to quickly and inexpensively produce replacement components or repair broken hardware in a Space Shuttle or Space Station environment. The intent of the task was to develop and fabricate an FDM system that was lightweight, compact, and required minimum power consumption to fabricate ABS plastic hardware in microgravity. The final product of the shortened task turned out to be a ground-based breadboard device, demonstrating miniaturization capability of the system.

Use of Field Programmable Gate Array Technology in Future Space Avionics

NASA Technical Reports Server (NTRS)

Ferguson, Roscoe C.; Tate, Robert

2005-01-01

Fulfilling NASA's new vision for space exploration requires the development of sustainable, flexible and fault tolerant spacecraft control systems. The traditional development paradigm consists of the purchase or fabrication of hardware boards with fixed processor and/or Digital Signal Processing (DSP) components interconnected via a standardized bus system. This is followed by the purchase and/or development of software. This paradigm has several disadvantages for the development of systems to support NASA's new vision. Building a system to be fault tolerant increases the complexity and decreases the performance of included software. Standard bus design and conventional implementation produces natural bottlenecks. Configuring hardware components in systems containing common processors and DSPs is difficult initially and expensive or impossible to change later. The existence of Hardware Description Languages (HDLs), the recent increase in performance, density and radiation tolerance of Field Programmable Gate Arrays (FPGAs), and Intellectual Property (IP) Cores provides the technology for reprogrammable Systems on a Chip (SOC). This technology supports a paradigm better suited for NASA's vision. Hardware and software production are melded for more effective development; they can both evolve together over time. Designers incorporating this technology into future avionics can benefit from its flexibility. Systems can be designed with improved fault isolation and tolerance using hardware instead of software. Also, these designs can be protected from obsolescence problems where maintenance is compromised via component and vendor availability.To investigate the flexibility of this technology, the core of the Central Processing Unit and Input/Output Processor of the Space Shuttle AP101S Computer were prototyped in Verilog HDL and synthesized into an Altera Stratix FPGA.

Space shuttle solid rocket booster cost-per-flight analysis technique

NASA Technical Reports Server (NTRS)

Forney, J. A.

1979-01-01

A cost per flight computer model is described which considers: traffic model, component attrition, hardware useful life, turnaround time for refurbishment, manufacturing rates, learning curves on the time to perform tasks, cost improvement curves on quantity hardware buys, inflation, spares philosophy, long lead, hardware funding requirements, and other logistics and scheduling constraints. Additional uses of the model include assessing the cost per flight impact of changing major space shuttle program parameters and searching for opportunities to make cost effective management decisions.

Comparison of ZigBee Replay Attacks Using a Universal Software Radio Peripheral and USB Radio

DTIC Science & Technology

2014-03-27

authentication code (CBC-MAC) CPU central processing unit CUT component under test db decibel dbm decibel referenced to one milliwatt FFD full- fuction ...categorized into two different types: full- fuction devices (FFDs) and reduced-function devices (RFDs). The difference between an FFD and an RFD is that...KillerBee Hardware. Although KillerBee can be used with any hardware that can interact with 802.15.4 networks, the primary development hardware is the

MSFC Skylab structures and mechanical systems mission evaluation

NASA Technical Reports Server (NTRS)

1974-01-01

A performance analysis for structural and mechanical major hardware systems and components is presented. Development background testing, modifications, and requirement adjustments are included. Functional narratives are provided for comparison purposes as are predicted design performance criterion. Each item is evaluated on an individual basis: that is, (1) history (requirements, design, manufacture, and test); (2) in-orbit performance (description and analysis); and (3) conclusions and recommendations regarding future space hardware application. Overall, the structural and mechanical performance of the Skylab hardware was outstanding.

Comparative Modal Analysis of Sieve Hardware Designs

NASA Technical Reports Server (NTRS)

Thompson, Nathaniel

2012-01-01

The CMTB Thwacker hardware operates as a testbed analogue for the Flight Thwacker and Sieve components of CHIMRA, a device on the Curiosity Rover. The sieve separates particles with a diameter smaller than 150 microns for delivery to onboard science instruments. The sieving behavior of the testbed hardware should be similar to the Flight hardware for the results to be meaningful. The elastodynamic behavior of both sieves was studied analytically using the Rayleigh Ritz method in conjunction with classical plate theory. Finite element models were used to determine the mode shapes of both designs, and comparisons between the natural frequencies and mode shapes were made. The analysis predicts that the performance of the CMTB Thwacker will closely resemble the performance of the Flight Thwacker within the expected steady state operating regime. Excitations of the testbed hardware that will mimic the flight hardware were recommended, as were those that will improve the efficiency of the sieving process.

Next Generation Wiring

NASA Technical Reports Server (NTRS)

Medelius, Petro; Jolley, Scott; Fitzpatrick, Lilliana; Vinje, Rubiela; Williams, Martha; Clayton, LaNetra; Roberson, Luke; Smith, Trent; Santiago-Maldonado, Edgardo

2007-01-01

Wiring is a major operational component on aerospace hardware that accounts for substantial weight and volumetric space. Over time wire insulation can age and fail, often leading to catastrophic events such as system failure or fire. The next generation of wiring must be reliable and sustainable over long periods of time. These features will be achieved by the development of a wire insulation capable of autonomous self-healing that mitigates failure before it reaches a catastrophic level. In order to develop a self-healing insulation material, three steps must occur. First, methods of bonding similar materials must be developed that are capable of being initiated autonomously. This process will lead to the development of a manual repair system for polyimide wire insulation. Second, ways to initiate these bonding methods that lead to materials that are similar to the primary insulation must be developed. Finally, steps one and two must be integrated to produce a material that has no residues from the process that degrades the insulating properties of the final repaired insulation. The self-healing technology, teamed with the ability to identify and locate damage, will greatly improve reliability and safety of electrical wiring of critical systems. This paper will address these topics, discuss the results of preliminary testing, and remaining development issues related to self-healing wire insulation.

An integrated approach to system design, reliability, and diagnosis

NASA Technical Reports Server (NTRS)

Patterson-Hine, F. A.; Iverson, David L.

1990-01-01

The requirement for ultradependability of computer systems in future avionics and space applications necessitates a top-down, integrated systems engineering approach for design, implementation, testing, and operation. The functional analyses of hardware and software systems must be combined by models that are flexible enough to represent their interactions and behavior. The information contained in these models must be accessible throughout all phases of the system life cycle in order to maintain consistency and accuracy in design and operational decisions. One approach being taken by researchers at Ames Research Center is the creation of an object-oriented environment that integrates information about system components required in the reliability evaluation with behavioral information useful for diagnostic algorithms. Procedures have been developed at Ames that perform reliability evaluations during design and failure diagnoses during system operation. These procedures utilize information from a central source, structured as object-oriented fault trees. Fault trees were selected because they are a flexible model widely used in aerospace applications and because they give a concise, structured representation of system behavior. The utility of this integrated environment for aerospace applications in light of our experiences during its development and use is described. The techniques for reliability evaluation and failure diagnosis are discussed, and current extensions of the environment and areas requiring further development are summarized.

Application of Diagnostic Analysis Tools to the Ares I Thrust Vector Control System

NASA Technical Reports Server (NTRS)

Maul, William A.; Melcher, Kevin J.; Chicatelli, Amy K.; Johnson, Stephen B.

2010-01-01

The NASA Ares I Crew Launch Vehicle is being designed to support missions to the International Space Station (ISS), to the Moon, and beyond. The Ares I is undergoing design and development utilizing commercial-off-the-shelf tools and hardware when applicable, along with cutting edge launch technologies and state-of-the-art design and development. In support of the vehicle s design and development, the Ares Functional Fault Analysis group was tasked to develop an Ares Vehicle Diagnostic Model (AVDM) and to demonstrate the capability of that model to support failure-related analyses and design integration. One important component of the AVDM is the Upper Stage (US) Thrust Vector Control (TVC) diagnostic model-a representation of the failure space of the US TVC subsystem. This paper first presents an overview of the AVDM, its development approach, and the software used to implement the model and conduct diagnostic analysis. It then uses the US TVC diagnostic model to illustrate details of the development, implementation, analysis, and verification processes. Finally, the paper describes how the AVDM model can impact both design and ground operations, and how some of these impacts are being realized during discussions of US TVC diagnostic analyses with US TVC designers.

An integrated approach to system design, reliability, and diagnosis

NASA Astrophysics Data System (ADS)

Patterson-Hine, F. A.; Iverson, David L.

1990-12-01

The requirement for ultradependability of computer systems in future avionics and space applications necessitates a top-down, integrated systems engineering approach for design, implementation, testing, and operation. The functional analyses of hardware and software systems must be combined by models that are flexible enough to represent their interactions and behavior. The information contained in these models must be accessible throughout all phases of the system life cycle in order to maintain consistency and accuracy in design and operational decisions. One approach being taken by researchers at Ames Research Center is the creation of an object-oriented environment that integrates information about system components required in the reliability evaluation with behavioral information useful for diagnostic algorithms. Procedures have been developed at Ames that perform reliability evaluations during design and failure diagnoses during system operation. These procedures utilize information from a central source, structured as object-oriented fault trees. Fault trees were selected because they are a flexible model widely used in aerospace applications and because they give a concise, structured representation of system behavior. The utility of this integrated environment for aerospace applications in light of our experiences during its development and use is described. The techniques for reliability evaluation and failure diagnosis are discussed, and current extensions of the environment and areas requiring further development are summarized.

FAULT PROPAGATION AND EFFECTS ANALYSIS FOR DESIGNING AN ONLINE MONITORING SYSTEM FOR THE SECONDARY LOOP OF A NUCLEAR POWER PLANT PART OF A HYBRID ENERGY SYSTEM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Huijuan; Diao, Xiaoxu; Li, Boyuan

This paper studies the propagation and effects of faults of critical components that pertain to the secondary loop of a nuclear power plant found in Nuclear Hybrid Energy Systems (NHES). This information is used to design an on-line monitoring (OLM) system which is capable of detecting and forecasting faults that are likely to occur during NHES operation. In this research, the causes, features, and effects of possible faults are investigated by simulating the propagation of faults in the secondary loop. The simulation is accomplished by using the Integrated System Failure Analysis (ISFA). ISFA is used for analyzing hardware and softwaremore » faults during the conceptual design phase. In this paper, the models of system components required by ISFA are initially constructed. Then, the fault propagation analysis is implemented, which is conducted under the bounds set by acceptance criteria derived from the design of an OLM system. The result of the fault simulation is utilized to build a database for fault detection and diagnosis, provide preventive measures, and propose an optimization plan for the OLM system.« less

SCADA alarms processing for wind turbine component failure detection

NASA Astrophysics Data System (ADS)

Gonzalez, E.; Reder, M.; Melero, J. J.

2016-09-01

Wind turbine failure and downtime can often compromise the profitability of a wind farm due to their high impact on the operation and maintenance (O&M) costs. Early detection of failures can facilitate the changeover from corrective maintenance towards a predictive approach. This paper presents a cost-effective methodology to combine various alarm analysis techniques, using data from the Supervisory Control and Data Acquisition (SCADA) system, in order to detect component failures. The approach categorises the alarms according to a reviewed taxonomy, turning overwhelming data into valuable information to assess component status. Then, different alarms analysis techniques are applied for two purposes: the evaluation of the SCADA alarm system capability to detect failures, and the investigation of the relation between components faults being followed by failure occurrences in others. Various case studies are presented and discussed. The study highlights the relationship between faulty behaviour in different components and between failures and adverse environmental conditions.

The Use of Probabilistic Methods to Evaluate the Systems Impact of Component Design Improvements on Large Turbofan Engines

NASA Technical Reports Server (NTRS)

Packard, Michael H.

2002-01-01

Probabilistic Structural Analysis (PSA) is now commonly used for predicting the distribution of time/cycles to failure of turbine blades and other engine components. These distributions are typically based on fatigue/fracture and creep failure modes of these components. Additionally, reliability analysis is used for taking test data related to particular failure modes and calculating failure rate distributions of electronic and electromechanical components. How can these individual failure time distributions of structural, electronic and electromechanical component failure modes be effectively combined into a top level model for overall system evaluation of component upgrades, changes in maintenance intervals, or line replaceable unit (LRU) redesign? This paper shows an example of how various probabilistic failure predictions for turbine engine components can be evaluated and combined to show their effect on overall engine performance. A generic model of a turbofan engine was modeled using various Probabilistic Risk Assessment (PRA) tools (Quantitative Risk Assessment Software (QRAS) etc.). Hypothetical PSA results for a number of structural components along with mitigation factors that would restrict the failure mode from propagating to a Loss of Mission (LOM) failure were used in the models. The output of this program includes an overall failure distribution for LOM of the system. The rank and contribution to the overall Mission Success (MS) is also given for each failure mode and each subsystem. This application methodology demonstrates the effectiveness of PRA for assessing the performance of large turbine engines. Additionally, the effects of system changes and upgrades, the application of different maintenance intervals, inclusion of new sensor detection of faults and other upgrades were evaluated in determining overall turbine engine reliability.

Independent Orbiter Assessment (IOA): Assessment of the backup flight system FMEA/CIL

NASA Technical Reports Server (NTRS)

Prust, E. E.; Ewell, J. J., Jr.; Hinsdale, L. W.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Backup Flight System (BFS) hardware, generating draft failure modes and Potential Critical Items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed NASA Post 51-L FMEA/CIL baseline. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter BFS hardware. The IOA product for the BFS analysis consisted of 29 failure mode worksheets that resulted in 21 Potential Critical Items (PCI) being identified. This product was originally compared with the proposed NASA BFS baseline and subsequently compared with the applicable Data Processing System (DPS), Electrical Power Distribution and Control (EPD and C), and Displays and Controls NASA CIL items. The comparisons determined if there were any results which had been found by the IOA but were not in the NASA baseline. The original assessment determined there were numerous failure modes and potential critical items in the IOA analysis that were not contained in the NASA BFS baseline. Conversely, the NASA baseline contained three FMEAs (IMU, ADTA, and Air Data Probe) for CIL items that were not identified in the IOA product.

Independent Orbiter Assessment (IOA): FMEA/CIL assessment

NASA Technical Reports Server (NTRS)

Hinsdale, L. W.; Swain, L. J.; Barnes, J. E.

1988-01-01

The McDonnell Douglas Astronautics Company (MDAC) was selected to perform an Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL). Direction was given by the Orbiter and GFE Projects Office to perform the hardware analysis and assessment using the instructions and ground rules defined in NSTS 22206. The IOA analysis featured a top-down approach to determine hardware failure modes, criticality, and potential critical items. To preserve independence, the analysis was accomplished without reliance upon the results contained within the NASA and Prime Contractor FMEA/CIL documentation. The assessment process compared the independently derived failure modes and criticality assignments to the proposed NASA post 51-L FMEA/CIL documentation. When possible, assessment issues were discussed and resolved with the NASA subsystem managers. Unresolved issues were elevated to the Orbiter and GFE Projects Office manager, Configuration Control Board (CCB), or Program Requirements Control Board (PRCB) for further resolution. The most important Orbiter assessment finding was the previously unknown stuck autopilot push-button criticality 1/1 failure mode. The worst case effect could cause loss of crew/vehicle when the microwave landing system is not active. It is concluded that NASA and Prime Contractor Post 51-L FMEA/CIL documentation assessed by IOA is believed to be technically accurate and complete. All CIL issues were resolved. No FMEA issues remain that have safety implications. Consideration should be given, however, to upgrading NSTS 22206 with definitive ground rules which more clearly spell out the limits of redundancy.

An Environmental for Hardware-in-the-Loop Formation Navigation and Control

NASA Technical Reports Server (NTRS)

Burns, Rich; Naasz, Bo; Gaylor, Dave; Higinbotham, John

2004-01-01

Recent interest in formation flying satellite systems has spurred a considerable amount of research in the relative navigation and control of satellites. Development in this area has included new estimation and control algorithms as well as sensor and actuator development specifically geared toward the relative control problem. This paper describes a simulation facility, the Formation Flying Test Bed (FFTB) at NASA Goddard Space Flight Center, which allows engineers to test new algorithms for the formation flying problem with relevant GN&C hardware in a closed loop simulation. The FFTB currently supports the inclusion of GPS receiver hardware in the simulation loop. Support for satellite crosslink ranging technology is at a prototype stage. This closed-loop, hardware inclusive simulation capability permits testing of navigation and control software in the presence of the actual hardware with which the algorithms must interact. This capability provides the navigation or control developer with a perspective on how the algorithms perform as part of the closed-loop system. In this paper, the overall design and evolution of the FFTB are presented. Each component of the FFTB is then described. Interfaces between the components of the FFTB are shown and the interfaces to and between navigation and control software are described. Finally, an example of closed-loop formation control with GPS receivers in the loop is presented.

Expert system for UNIX system reliability and availability enhancement

NASA Astrophysics Data System (ADS)

Xu, Catherine Q.

1993-02-01

Highly reliable and available systems are critical to the airline industry. However, most off-the-shelf computer operating systems and hardware do not have built-in fault tolerant mechanisms, the UNIX workstation is one example. In this research effort, we have developed a rule-based Expert System (ES) to monitor, command, and control a UNIX workstation system with hot-standby redundancy. The ES on each workstation acts as an on-line system administrator to diagnose, report, correct, and prevent certain types of hardware and software failures. If a primary station is approaching failure, the ES coordinates the switch-over to a hot-standby secondary workstation. The goal is to discover and solve certain fatal problems early enough to prevent complete system failure from occurring and therefore to enhance system reliability and availability. Test results show that the ES can diagnose all targeted faulty scenarios and take desired actions in a consistent manner regardless of the sequence of the faults. The ES can perform designated system administration tasks about ten times faster than an experienced human operator. Compared with a single workstation system, our hot-standby redundancy system downtime is predicted to be reduced by more than 50 percent by using the ES to command and control the system.

Expert System for UNIX System Reliability and Availability Enhancement

NASA Technical Reports Server (NTRS)

Xu, Catherine Q.

1993-01-01

Highly reliable and available systems are critical to the airline industry. However, most off-the-shelf computer operating systems and hardware do not have built-in fault tolerant mechanisms, the UNIX workstation is one example. In this research effort, we have developed a rule-based Expert System (ES) to monitor, command, and control a UNIX workstation system with hot-standby redundancy. The ES on each workstation acts as an on-line system administrator to diagnose, report, correct, and prevent certain types of hardware and software failures. If a primary station is approaching failure, the ES coordinates the switch-over to a hot-standby secondary workstation. The goal is to discover and solve certain fatal problems early enough to prevent complete system failure from occurring and therefore to enhance system reliability and availability. Test results show that the ES can diagnose all targeted faulty scenarios and take desired actions in a consistent manner regardless of the sequence of the faults. The ES can perform designated system administration tasks about ten times faster than an experienced human operator. Compared with a single workstation system, our hot-standby redundancy system downtime is predicted to be reduced by more than 50 percent by using the ES to command and control the system.

Informatics in radiology (infoRAD): A complete continuous-availability PACS archive server.

PubMed

Liu, Brent J; Huang, H K; Cao, Fei; Zhou, Michael Z; Zhang, Jianguo; Mogel, Greg

2004-01-01

The operational reliability of the picture archiving and communication system (PACS) server in a filmless hospital environment is always a major concern because server failure could cripple the entire PACS operation. A simple, low-cost, continuous-availability (CA) PACS archive server was designed and developed. The server makes use of a triple modular redundancy (TMR) system with a simple majority voting logic that automatically identifies a faulty module and removes it from service. The remaining two modules continue normal operation with no adverse effects on data flow or system performance. In addition, the server is integrated with two external mass storage devices for short- and long-term storage. Evaluation and testing of the server were conducted with laboratory experiments in which hardware failures were simulated to observe recovery time and the resumption of normal data flow. The server provides maximum uptime (99.999%) for end users while ensuring the transactional integrity of all clinical PACS data. Hardware failure has only minimal impact on performance, with no interruption of clinical data flow or loss of data. As hospital PACS become more widespread, the need for CA PACS solutions will increase. A TMR CA PACS archive server can reliably help achieve CA in this setting. Copyright RSNA, 2004

Space tug propulsion system failure mode, effects and criticality analysis

NASA Technical Reports Server (NTRS)

Boyd, J. W.; Hardison, E. P.; Heard, C. B.; Orourke, J. C.; Osborne, F.; Wakefield, L. T.

1972-01-01

For purposes of the study, the propulsion system was considered as consisting of the following: (1) main engine system, (2) auxiliary propulsion system, (3) pneumatic system, (4) hydrogen feed, fill, drain and vent system, (5) oxygen feed, fill, drain and vent system, and (6) helium reentry purge system. Each component was critically examined to identify possible failure modes and the subsequent effect on mission success. Each space tug mission consists of three phases: launch to separation from shuttle, separation to redocking, and redocking to landing. The analysis considered the results of failure of a component during each phase of the mission. After the failure modes of each component were tabulated, those components whose failure would result in possible or certain loss of mission or inability to return the Tug to ground were identified as critical components and a criticality number determined for each. The criticality number of a component denotes the number of mission failures in one million missions due to the loss of that component. A total of 68 components were identified as critical with criticality numbers ranging from 1 to 2990.

Graphics mini manual

NASA Technical Reports Server (NTRS)

Taylor, Nancy L.; Randall, Donald P.; Bowen, John T.; Johnson, Mary M.; Roland, Vincent R.; Matthews, Christine G.; Gates, Raymond L.; Skeens, Kristi M.; Nolf, Scott R.; Hammond, Dana P.

1990-01-01

The computer graphics capabilities available at the Center are introduced and their use is explained. More specifically, the manual identifies and describes the various graphics software and hardware components, details the interfaces between these components, and provides information concerning the use of these components at LaRC.

Cone-beam micro-CT system based on LabVIEW software.

PubMed

Ionita, Ciprian N; Hoffmann, Keneth R; Bednarek, Daniel R; Chityala, Ravishankar; Rudin, Stephen

2008-09-01

Construction of a cone-beam computed tomography (CBCT) system for laboratory research usually requires integration of different software and hardware components. As a result, building and operating such a complex system require the expertise of researchers with significantly different backgrounds. Additionally, writing flexible code to control the hardware components of a CBCT system combined with designing a friendly graphical user interface (GUI) can be cumbersome and time consuming. An intuitive and flexible program structure, as well as the program GUI for CBCT acquisition, is presented in this note. The program was developed in National Instrument's Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW) graphical language and is designed to control a custom-built CBCT system but has been also used in a standard angiographic suite. The hardware components are commercially available to researchers and are in general provided with software drivers which are LabVIEW compatible. The program structure was designed as a sequential chain. Each step in the chain takes care of one or two hardware commands at a time; the execution of the sequence can be modified according to the CBCT system design. We have scanned and reconstructed over 200 specimens using this interface and present three examples which cover different areas of interest encountered in laboratory research. The resulting 3D data are rendered using a commercial workstation. The program described in this paper is available for use or improvement by other researchers.

Diagnostic emulation: Implementation and user's guide

NASA Technical Reports Server (NTRS)

Becher, Bernice

1987-01-01

The Diagnostic Emulation Technique was developed within the System Validation Methods Branch as a part of the development of methods for the analysis of the reliability of highly reliable, fault tolerant digital avionics systems. This is a general technique which allows for the emulation of a digital hardware system. The technique is general in the sense that it is completely independent of the particular target hardware which is being emulated. Parts of the system are described and emulated at the logic or gate level, while other parts of the system are described and emulated at the functional level. This algorithm allows for the insertion of faults into the system, and for the observation of the response of the system to these faults. This allows for controlled and accelerated testing of system reaction to hardware failures in the target machine. This document describes in detail how the algorithm was implemented at NASA Langley Research Center and gives instructions for using the system.

Proceedings of the IDA Workshop on Formal Specification and Verification of Ada (Trade Name) (3rd) Held in Research Triangle Park, North Carolina on 14-16 May 1986

DTIC Science & Technology

1986-08-01

sensitivity to software or hardware failures (bit transformation, register perversion, interface failures, etc .) which could cause the system to operate in a...of systems . She pointed to the need for 40 safety concerns in a continually growing number of computer applications (e.g., monitor and/or control of...informal, definition. Finally, the definition is based on the SMoLCS (Structured Monitored Linear Concurrent Systems ) methodology, an approach to the

[Research and implementation of a real-time monitoring system for running status of medical monitors based on the internet of things].

PubMed

Li, Yiming; Qian, Mingli; Li, Long; Li, Bin

2014-07-01

This paper proposed a real-time monitoring system for running status of medical monitors based on the internet of things. In the aspect of hardware, a solution of ZigBee networks plus 470 MHz networks is proposed. In the aspect of software, graphical display of monitoring interface and real-time equipment failure alarm is implemented. The system has the function of remote equipment failure detection and wireless localization, which provides a practical and effective method for medical equipment management.

OARSI Clinical Trials Recommendations for Hip Imaging in Osteoarthritis

PubMed Central

Gold, Garry E.; Cicuttini, Flavia; Crema, Michel D.; Eckstein, Felix; Guermazi, Ali; Kijowski, Richard; Link, Thomas M.; Maheu, Emmanuel; Martel-Pelletier, Johanne; Miller, Colin G.; Pelletier, Jean-Pierre; Peterfy, Charles G.; Potter, Hollis G.; Roemer, Frank W.; Hunter, David. J

2015-01-01

Imaging of hip in osteoarthritis (OA) has seen considerable progress in the past decade, with the introduction of new techniques that may be more sensitive to structural disease changes. The purpose of this expert opinion, consensus driven recommendation is to provide detail on how to apply hip imaging in disease modifying clinical trials. It includes information on acquisition methods/ techniques (including guidance on positioning for radiography, sequence/protocol recommendations/ hardware for MRI); commonly encountered problems (including positioning, hardware and coil failures, artifacts associated with various MRI sequences); quality assurance/ control procedures; measurement methods; measurement performance (reliability, responsiveness, and validity); recommendations for trials; and research recommendations. PMID:25952344

Stress Analysis of B-52B and B-52H Air-Launching Systems Failure-Critical Structural Components

NASA Technical Reports Server (NTRS)

Ko, William L.

2005-01-01

The operational life analysis of any airborne failure-critical structural component requires the stress-load equation, which relates the applied load to the maximum tangential tensile stress at the critical stress point. The failure-critical structural components identified are the B-52B Pegasus pylon adapter shackles, B-52B Pegasus pylon hooks, B-52H airplane pylon hooks, B-52H airplane front fittings, B-52H airplane rear pylon fitting, and the B-52H airplane pylon lower sway brace. Finite-element stress analysis was performed on the said structural components, and the critical stress point was located and the stress-load equation was established for each failure-critical structural component. The ultimate load, yield load, and proof load needed for operational life analysis were established for each failure-critical structural component.

Pyrotechnic system failures: Causes and prevention

NASA Technical Reports Server (NTRS)

Bement, Laurence J.

1988-01-01

Although pyrotechnics have successfully accomplished many critical mechanical spacecraft functions, such as ignition, severance, jettisoning and valving (excluding propulsion), failures continue to occur. Provided is a listing of 84 failures of pyrotechnic hardware with completed design over a 23-year period, compiled informally by experts from every NASA Center, as well as the Air Force Space Division and the Naval Surface Warfare Center. Analyses are presented as to when and where these failures occurred, their technical source or cause, followed by the reasons why and how these kinds of failures persist. The major contributor is a fundamental lack of understanding of the functional mechanisms of pyrotechnic devices and systems, followed by not recognizing pyrotechnics as an engineering technology, insufficient manpower with hands-on experience, too few test facilities, and inadequate guidelines and specifications for design, development, qualification and acceptance. Recommendations are made on both a managerial and technical basis to prevent failures, increase reliability, improve existing and future designs, and develop the technology to meet future requirements.

Failure analysis of storage tank component in LNG regasification unit using fault tree analysis method (FTA)

NASA Astrophysics Data System (ADS)

Mulyana, Cukup; Muhammad, Fajar; Saad, Aswad H.; Mariah, Riveli, Nowo

2017-03-01

Storage tank component is the most critical component in LNG regasification terminal. It has the risk of failure and accident which impacts to human health and environment. Risk assessment is conducted to detect and reduce the risk of failure in storage tank. The aim of this research is determining and calculating the probability of failure in regasification unit of LNG. In this case, the failure is caused by Boiling Liquid Expanding Vapor Explosion (BLEVE) and jet fire in LNG storage tank component. The failure probability can be determined by using Fault Tree Analysis (FTA). Besides that, the impact of heat radiation which is generated is calculated. Fault tree for BLEVE and jet fire on storage tank component has been determined and obtained with the value of failure probability for BLEVE of 5.63 × 10-19 and for jet fire of 9.57 × 10-3. The value of failure probability for jet fire is high enough and need to be reduced by customizing PID scheme of regasification LNG unit in pipeline number 1312 and unit 1. The value of failure probability after customization has been obtained of 4.22 × 10-6.

Analysis of systems hardware flown on LDEF. Results of the systems special investigation group

NASA Technical Reports Server (NTRS)

Dursch, Harry W.; Spear, W. Steve; Miller, Emmett A.; Bohnhoff-Hlavacek, Gail L.; Edelman, Joel

1992-01-01

The Long Duration Exposure Facility (LDEF) was retrieved after spending 69 months in low Earth orbit (LEO). LDEF carried a remarkable variety of mechanical, electrical, thermal, and optical systems, subsystems, and components. The Systems Special Investigation Group (Systems SIG) was formed to investigate the effects of the long duration exposure to LEO on systems related hardware and to coordinate and collate all systems analysis of LDEF hardware. Discussed here is the status of the LDEF Systems SIG investigation through the end of 1991.

Analysis of systems hardware flown on LDEF. Results of the systems special investigation group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dursch, H.W.; Spear, W.S.; Miller, E.A.

1992-04-01

The Long Duration Exposure Facility (LDEF) was retrieved after spending 69 months in low Earth orbit (LEO). LDEF carried a remarkable variety of mechanical, electrical, thermal, and optical systems, subsystems, and components. The Systems Special Investigation Group (Systems SIG) was formed to investigate the effects of the long duration exposure to LEO on systems related hardware and to coordinate and collate all systems analysis of LDEF hardware. Discussed here is the status of the LDEF Systems SIG investigation through the end of 1991.

Stretched Lens Array (SLA) Photovoltaic Concentrator Hardware Development and Testing

NASA Technical Reports Server (NTRS)

Piszczor, Michael; O'Neill, Mark J.; Eskenazi, Michael

2003-01-01

Over the past two years, the Stretched Lens Array (SLA) photovoltaic concentrator has evolved, under a NASA contract, from a concept with small component demonstrators to operational array hardware that is ready for space validation testing. A fully-functional four panel SLA solar array has been designed, built and tested. This paper will summarize the focus of the hardware development effort, discuss the results of recent testing conducted under this program and present the expected performance of a full size 7kW array designed to meet the requirements of future space missions.

Analysis of systems hardware flown on LDEF: New findings and comparison to other retrieved spacecraft hardware

NASA Technical Reports Server (NTRS)

Dursch, Harry; Bohnhoff-Hlavacek, Gail; Blue, Donald; Hansen, Patricia

1995-01-01

The Long Duration Exposure Facility (LDEF) was retrieved in 1990 after spending 69 months in low-earth-orbit (LEO). A wide variety of mechanical, electrical, thermal, and optical systems, subsystems, and components were flown on LDEF. The Systems Special Investigation Group (Systems SIG) was formed by NASA to investigate the effects of the 69 month exposure on systems related hardware and to coordinate and collate all systems analysis of LDEF hardware. This report is the Systems SIG final report which updates earlier findings and compares LDEF systems findings to results from other retrieved spacecraft hardware such as Hubble Space Telescope. Also included are sections titled (1) Effects of Long Duration Space Exposure on Optical Scatter, (2) Contamination Survey of LDEF, and (3) Degradation of Optical Materials in Space.

Improving the efficiency of a user-driven learning system with reconfigurable hardware. Application to DNA splicing.

PubMed

Lemoine, E; Merceron, D; Sallantin, J; Nguifo, E M

1999-01-01

This paper describes a new approach to problem solving by splitting up problem component parts between software and hardware. Our main idea arises from the combination of two previously published works. The first one proposed a conceptual environment of concept modelling in which the machine and the human expert interact. The second one reported an algorithm based on reconfigurable hardware system which outperforms any kind of previously published genetic data base scanning hardware or algorithms. Here we show how efficient the interaction between the machine and the expert is when the concept modelling is based on reconfigurable hardware system. Their cooperation is thus achieved with an real time interaction speed. The designed system has been partially applied to the recognition of primate splice junctions sites in genetic sequences.

Analysis of systems hardware flown on LDEF: New findings and comparison to other retrieved spacecraft hardware

NASA Astrophysics Data System (ADS)

Dursch, Harry; Bohnhoff-Hlavacek, Gail; Blue, Donald; Hansen, Patricia

1995-09-01

The Long Duration Exposure Facility (LDEF) was retrieved in 1990 after spending 69 months in low-earth-orbit (LEO). A wide variety of mechanical, electrical, thermal, and optical systems, subsystems, and components were flown on LDEF. The Systems Special Investigation Group (Systems SIG) was formed by NASA to investigate the effects of the 69 month exposure on systems related hardware and to coordinate and collate all systems analysis of LDEF hardware. This report is the Systems SIG final report which updates earlier findings and compares LDEF systems findings to results from other retrieved spacecraft hardware such as Hubble Space Telescope. Also included are sections titled (1) Effects of Long Duration Space Exposure on Optical Scatter, (2) Contamination Survey of LDEF, and (3) Degradation of Optical Materials in Space.

Intrinsic Hardware Evolution for the Design and Reconfiguration of Analog Speed Controllers for a DC Motor

NASA Technical Reports Server (NTRS)

Gwaltney, David A.; Ferguson, Michael I.

2003-01-01

Evolvable hardware provides the capability to evolve analog circuits to produce amplifier and filter functions. Conventional analog controller designs employ these same functions. Analog controllers for the control of the shaft speed of a DC motor are evolved on an evolvable hardware platform utilizing a second generation Field Programmable Transistor Array (FPTA2). The performance of an evolved controller is compared to that of a conventional proportional-integral (PI) controller. It is shown that hardware evolution is able to create a compact design that provides good performance, while using considerably less functional electronic components than the conventional design. Additionally, the use of hardware evolution to provide fault tolerance by reconfiguring the design is explored. Experimental results are presented showing that significant recovery of capability can be made in the face of damaging induced faults.

Detailed results of ASTP experiment MA-011. [biological processing facility in space

NASA Technical Reports Server (NTRS)

Seaman, G. V. F.; Allen, R. E.; Barlow, G. H.; Bier, M.

1976-01-01

This experiment was developed in order to conduct engineering and operational tests of electrokinetic equipment in a micro-gravity environment. The experimental hardware in general functioned as planned and electrophoretic separations were obtained in space. The results indicated the development of satisfactory sample collection, return, and preservation techniques. The application of a near-zero zeta potential interior wall coating to the experimental columns, confirmation of biocompatibility of all appropriate hardware components, and use of a sterile operating environment provided a significant step forward in the development of a biological processing facility in space. A separation of a test of aldehyde-fixed rabbit, human, and horse red blood cells was obtained. Human kidney cells were separated into several components and viable cells returned to earth. The isotachophoretic separation of red cells was also demonstrated. Problems associated with the hardware led to a lack of success in the attempt to separate subpopulations of human lymphocytes.

Status of the Boeing Dish Engine Critical Component Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brau, H.W.; Diver, R.B.; Nelving, H.

1999-01-08

The Boeing Company's Dish Engine Critical Component (DECC) project started in April of 1998. It is a continuation of a solar energy program started by McDonnell Douglas (now Boeing) and United Stirling of Sweden in the mid 1980s. The overall objectives, schedule, and status of this project are presented in this paper. The hardware test configuration, hardware background, operation, and test plans are also discussed. A summary is given of the test data, which includes the daily power performance, generated energy, working-gas usage, mirror reflectivity, solar insolation, on-sun track time, generating time, and system availability. The system performance based uponmore » the present test data is compared to test data from the 1984/88 McDonnell Douglas/United Stirling AB/Southem California Edison test program. The test data shows that the present power, energy, and mirror performance is comparable to when the hardware was first manufactured 14 years ago.« less

Status of the Boeing Dish Engine Critical Component project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stone, K.W.; Nelving, H.; Braun, H.W.

1999-07-01

The Boeing Company's Dish Engine Critical Component (DECC) project started in April of 1998. It is a continuation of a solar energy program started by McDonnel Douglas (now Boeing) and United Stirling of Sweden in the mid 1980s. The overall objectives, schedule, and status of this project are presented in this paper. The hardware test configuration, hardware background, operation, and test plans are also discussed. A summary is given of the test data, which includes the daily power performance, generated energy, working-gas usage, mirror reflectivity, solar insolation, on-sun track time. Generating time, and system availability. The system performance based uponmore » the present test data is compared to test data from the 1984/88 McDonnel Douglas/United Stirling AB/Southern California Edison test program. The test data shows that the present power, energy, and mirror performance is comparable to when the hardware was first manufactured 14 years ago.« less

Compound estimation procedures in reliability

NASA Technical Reports Server (NTRS)

Barnes, Ron

1990-01-01

At NASA, components and subsystems of components in the Space Shuttle and Space Station generally go through a number of redesign stages. While data on failures for various design stages are sometimes available, the classical procedures for evaluating reliability only utilize the failure data on the present design stage of the component or subsystem. Often, few or no failures have been recorded on the present design stage. Previously, Bayesian estimators for the reliability of a single component, conditioned on the failure data for the present design, were developed. These new estimators permit NASA to evaluate the reliability, even when few or no failures have been recorded. Point estimates for the latter evaluation were not possible with the classical procedures. Since different design stages of a component (or subsystem) generally have a good deal in common, the development of new statistical procedures for evaluating the reliability, which consider the entire failure record for all design stages, has great intuitive appeal. A typical subsystem consists of a number of different components and each component has evolved through a number of redesign stages. The present investigations considered compound estimation procedures and related models. Such models permit the statistical consideration of all design stages of each component and thus incorporate all the available failure data to obtain estimates for the reliability of the present version of the component (or subsystem). A number of models were considered to estimate the reliability of a component conditioned on its total failure history from two design stages. It was determined that reliability estimators for the present design stage, conditioned on the complete failure history for two design stages have lower risk than the corresponding estimators conditioned only on the most recent design failure data. Several models were explored and preliminary models involving bivariate Poisson distribution and the Consael Process (a bivariate Poisson process) were developed. Possible short comings of the models are noted. An example is given to illustrate the procedures. These investigations are ongoing with the aim of developing estimators that extend to components (and subsystems) with three or more design stages.

The software architecture of the camera for the ASTRI SST-2M prototype for the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Sangiorgi, Pierluca; Capalbi, Milvia; Gimenes, Renato; La Rosa, Giovanni; Russo, Francesco; Segreto, Alberto; Sottile, Giuseppe; Catalano, Osvaldo

2016-07-01

The purpose of this contribution is to present the current status of the software architecture of the ASTRI SST-2M Cherenkov Camera. The ASTRI SST-2M telescope is an end-to-end prototype for the Small Size Telescope of the Cherenkov Telescope Array. The ASTRI camera is an innovative instrument based on SiPM detectors and has several internal hardware components. In this contribution we will give a brief description of the hardware components of the camera of the ASTRI SST-2M prototype and of their interconnections. Then we will present the outcome of the software architectural design process that we carried out in order to identify the main structural components of the camera software system and the relationships among them. We will analyze the architectural model that describes how the camera software is organized as a set of communicating blocks. Finally, we will show where these blocks are deployed in the hardware components and how they interact. We will describe in some detail, the physical communication ports and external ancillary devices management, the high precision time-tag management, the fast data collection and the fast data exchange between different camera subsystems, and the interfacing with the external systems.

Application of Weibull analysis to SSME hardware

NASA Technical Reports Server (NTRS)

Gray, L. A. B.

1986-01-01

Generally, it has been documented that the wearing of engine parts forms a failure distribution which can be approximated by a function developed by Weibull. The purpose here is to examine to what extent the Weibull distribution approximates failure data for designated engine parts of the Space Shuttle Main Engine (SSME). The current testing certification requirements will be examined in order to establish confidence levels. An examination of the failure history of SSME parts/assemblies (turbine blades, main combustion chamber, or high pressure fuel pump first stage impellers) which are limited in usage by time or starts will be done by using updated Weibull techniques. Efforts will be made by the investigator to predict failure trends by using Weibull techniques for SSME parts (turbine temperature sensors, chamber pressure transducers, actuators, and controllers) which are not severely limited by time or starts.

Socket position determines hip resurfacing 10-year survivorship.

PubMed

Amstutz, Harlan C; Le Duff, Michel J; Johnson, Alicia J

2012-11-01

Modern metal-on-metal hip resurfacing arthroplasty designs have been used for over a decade. Risk factors for short-term failure include small component size, large femoral head defects, low body mass index, older age, high level of sporting activity, and component design, and it is established there is a surgeon learning curve. Owing to failures with early surgical techniques, we developed a second-generation technique to address those failures. However, it is unclear whether the techniques affected the long-term risk factors. We (1) determined survivorship for hips implanted with the second-generation cementing technique; (2) identified the risk factors for failure in these patients; and (3) determined the effect of the dominant risk factors on the observed modes of failure. We retrospectively reviewed the first 200 hips (178 patients) implanted using our second-generation surgical technique, which consisted of improvements in cleaning and drying the femoral head before and during cement application. There were 129 men and 49 women. Component orientation and contact patch to rim distance were measured. We recorded the following modes of failure: femoral neck fracture, femoral component loosening, acetabular component loosening, wear, dislocation, and sepsis. The minimum followup was 25 months (mean, 106.5 months; range, 25-138 months). Twelve hips were revised. Kaplan-Meier survivorship was 98.0% at 5 years and 94.3% at 10 years. The only variable associated with revision was acetabular component position. Contact patch to rim distance was lower in hips that dislocated, were revised for wear, or were revised for acetabular loosening. The dominant modes of failure were related to component wear or acetabular component loosening. Acetabular component orientation, a factor within the surgeon's control, determines the long-term success of our current hip resurfacing techniques. Current techniques have changed the modes of failure from aseptic femoral failure to wear or loosening of the acetabular component. Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Social communication: a potent force for change.

PubMed

Lone, S

1983-12-01

Some of the strongest challenges to established communication structures emerge from the development arena. 1 element of the challenges comes from those working to place communication between deprived communities and those providing them expertise at the center of development planning. Communication specialists maintain that human communication is the pivot on which balances the success or failure of the whole process of development as well as individual programs. Yet, the vast majority of development programs are conceived and executed without a serious communication component. Communication personnel are irritated by the approach of planning first, and communicating only after a failure. As more and more after the fact appeals are heard, it is becoming clearer to planners that communication is more than another hardware component consisting of posters, radio messages, and so on, but a central and decisive factor of any program. The attempt to raise communications to a more appropriate place in the development context has been aided greatly by recent evidence of its impact. Among those who must be classified as successful in fully investigating their target group and understanding how to communicate with them are the commercial manufacturers. Their advertising campaigns have revolutionized consumption habits and lifestyles across the world. An increasing number of voices, recognizing the impact of commercial advertising, are advocating that their techniques be adopted in the promotion of social development. Richard Manoff is one experienced advertising man who has used his commercial skills to promote developmental messages. He maintains that there is no idea that cannot be promoted as are commercial products. Changes in communication strategies will not by themselves eliminate the most fundamental problem facing humanity, i.e., the eradication of poverty, but they can contribute to that goal. A comprehensive communication strategy can help awaken people to release their energies in the service of development.

Real-time computing platform for spiking neurons (RT-spike).

PubMed

Ros, Eduardo; Ortigosa, Eva M; Agís, Rodrigo; Carrillo, Richard; Arnold, Michael

2006-07-01

A computing platform is described for simulating arbitrary networks of spiking neurons in real time. A hybrid computing scheme is adopted that uses both software and hardware components to manage the tradeoff between flexibility and computational power; the neuron model is implemented in hardware and the network model and the learning are implemented in software. The incremental transition of the software components into hardware is supported. We focus on a spike response model (SRM) for a neuron where the synapses are modeled as input-driven conductances. The temporal dynamics of the synaptic integration process are modeled with a synaptic time constant that results in a gradual injection of charge. This type of model is computationally expensive and is not easily amenable to existing software-based event-driven approaches. As an alternative we have designed an efficient time-based computing architecture in hardware, where the different stages of the neuron model are processed in parallel. Further improvements occur by computing multiple neurons in parallel using multiple processing units. This design is tested using reconfigurable hardware and its scalability and performance evaluated. Our overall goal is to investigate biologically realistic models for the real-time control of robots operating within closed action-perception loops, and so we evaluate the performance of the system on simulating a model of the cerebellum where the emulation of the temporal dynamics of the synaptic integration process is important.

HiCAT Software Infrastructure: Safe hardware control with object oriented Python

NASA Astrophysics Data System (ADS)

Moriarty, Christopher; Brooks, Keira; Soummer, Remi

2018-01-01

High contrast imaging for Complex Aperture Telescopes (HiCAT) is a testbed designed to demonstrate coronagraphy and wavefront control for segmented on-axis space telescopes such as envisioned for LUVOIR. To limit the air movements in the testbed room, software interfaces for several different hardware components were developed to completely automate operations. When developing software interfaces for many different pieces of hardware, unhandled errors are commonplace and can prevent the software from properly closing a hardware resource. Some fragile components (e.g. deformable mirrors) can be permanently damaged because of this. We present an object oriented Python-based infrastructure to safely automate hardware control and optical experiments. Specifically, conducting high-contrast imaging experiments while monitoring humidity and power status along with graceful shutdown processes even for unexpected errors. Python contains a construct called a “context manager” that allows you define code to run when a resource is opened or closed. Context managers ensure that a resource is properly closed, even when unhandled errors occur. Harnessing the context manager design, we also use Python’s multiprocessing library to monitor humidity and power status without interrupting the experiment. Upon detecting a safety problem, the master process sends an event to the child process that triggers the context managers to gracefully close any open resources. This infrastructure allows us to queue up several experiments and safely operate the testbed without a human in the loop.

An Environment for Hardware-in-the-Loop Formation Navigation and Control Simulation

NASA Technical Reports Server (NTRS)

Burns, Rich

2004-01-01

Recent interest in formation flying satellite systems has spurred a considerable amount of research in the relative navigation and control of satellites. Development in this area has included new estimation and control algorithms as well as sensor and actuator development specifically geared toward the relative control problem. This paper describes a simulation facility, the Formation Flying Testbed (FFTB) at NASA's Goddard Space Flight Center, which allows engineers to test new algorithms for the formation flying problem with relevant GN&C hardware in a closed loop simulation. The FFTB currently supports the injection of GPS receiver hardware into the simulation loop, and support for satellite crosslink ranging technology is at a prototype stage. This closed-loop, hardware inclusive simulation capability permits testing of navigation and control software in the presence of the actual hardware with which the algorithms must interact. This capability provides the navigation or control developer with a perspective on how the algorithms perform as part of the closed-loop system. In this paper, the overall design and evolution of the FFTB are presented. Each component of the FFTB is then described in detail. Interfaces between the components of the FFTB are shown and the interfaces to and between navigation and control software are described in detail. Finally, an example of closed-loop formation control with GPS receivers in the loop is presented and results are analyzed.

Survivorship analysis of failure pattern after revision total hip arthroplasty.

PubMed

Retpen, J B; Varmarken, J E; Jensen, J S

1989-12-01

Failure, defined as established indication for or performed re-revision of one or both components, was analyzed using survivorship methods in 306 revision total hip arthroplasties. The longevity of revision total hip arthroplasties was inferior to that of previously reported primary total hip arthroplasties. The overall survival curve was two-phased, with a late failure period associated with aseptic loosening of one or both components and an early failure period associated with causes of failure other than loosening. Separate survival curves for aseptic loosening of femoral and acetabular components showed late and almost simultaneous decline, but with a tendency toward a higher rate of failure for the femoral component. No differences in survival could be found between the Stanmore, Lubinus standard, and Lubinus long-stemmed femoral components. A short interval between the index operation and the revision and intraoperative and postoperative complications were risk factors for early failure. Young age was a risk factor for aseptic loosening of the femoral component. Intraoperative fracture of the femoral shaft was not a risk factor for secondary loosening. No difference in survival was found between primary cemented total arthroplasty and primary noncemented hemiarthroplasty.

Source Data Applicability Impacts on Epistemic Uncertainty for Launch Vehicle Fault Tree Models

NASA Technical Reports Server (NTRS)

Al Hassan, Mohammad; Novack, Steven D.; Ring, Robert W.

2016-01-01

Launch vehicle systems are designed and developed using both heritage and new hardware. Design modifications to the heritage hardware to fit new functional system requirements can impact the applicability of heritage reliability data. Risk estimates for newly designed systems must be developed from generic data sources such as commercially available reliability databases using reliability prediction methodologies, such as those addressed in MIL-HDBK-217F. Failure estimates must be converted from the generic environment to the specific operating environment of the system where it is used. In addition, some qualification of applicability for the data source to the current system should be made. Characterizing data applicability under these circumstances is crucial to developing model estimations that support confident decisions on design changes and trade studies. This paper will demonstrate a data-source applicability classification method for assigning uncertainty to a target vehicle based on the source and operating environment of the originating data. The source applicability is determined using heuristic guidelines while translation of operating environments is accomplished by applying statistical methods to MIL-HDK-217F tables. The paper will provide a case study example by translating Ground Benign (GB) and Ground Mobile (GM) to the Airborne Uninhabited Fighter (AUF) environment for three electronic components often found in space launch vehicle control systems. The classification method will be followed by uncertainty-importance routines to assess the need to for more applicable data to reduce uncertainty.

Development of high-availability ATCA/PCIe data acquisition instrumentation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Correia, Miguel; Sousa, Jorge; Batista, Antonio J.N.

2015-07-01

Latest Fusion energy experiments envision a quasi-continuous operation regime. In consequence, the largest experimental devices, currently in development, specify high-availability (HA) requirements for the whole plant infrastructure. HA features enable the whole facility to perform seamlessly in the case of failure of any of its components, coping with the increasing duration of plasma discharges (steady-state) and assuring safety of equipment, people, environment and investment. IPFN developed a control and data acquisition system, aiming for fast control of advanced Fusion devices, which is thus required to provide such HA features. The system is based on in-house developed Advanced Telecommunication Computing Architecturemore » (ATCA) instrumentation modules - IO blades and data switch blades, establishing a PCIe network on the ATCA shelf's back-plane. The data switch communicates to an external host computer through a PCIe data network. At the hardware management level, the system architecture takes advantage of ATCA native redundancy and hot swap specifications to implement fail-over substitution of IO or data switch blades. A redundant host scheme is also supported by the ATCA/PCIe platform. At the software level, PCIe provides implementation of hot plug services, which translate the hardware changes to the corresponding software/operating system devices. The paper presents how the ATCA and PCIe based system can be setup to perform with the desired degree of HA, thus being suitable for advanced Fusion control and data acquisition systems. (authors)« less

Space environmental effects observed on the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Edelman, Joel E.; Mason, James B.

1995-01-01

The Hubble Space Telescope (HST) Repair Mission of December, 1993, was first and foremost a mission to improve the performance of the observatory. But for a specialized segment of the aerospace industry, the primary interest is in the return to Earth of numerous pieces of the HST hardware, pieces which have been replaced, repaired, improved, or superseded. The returned hardware is of interest because of the information it potentially carries about the effects of exposure to the space environment for three and a half years. Like the LDEF retrieval mission four years ago, the HST repair mission is of interest to many engineering disciplines, including all of the disciplines represented by the LDEF Special Investigation Groups (SIG's). There is particular interest in the evaluation of specific materials and systems in the returned components. Some coated surfaces have been processed with materials which are newer and still in use by, or under consideration for, other spacecraft in a variety of stages of development. Several of the systems are being returned because a specific failure or anomaly has been observed and thus there is, at the outset, a specific investigative trail that needs to be followed. These systems are much more complex than those flown on LDEF and, in two instances, comprised state-of-the-art science instruments. Further, the parts used in these systems generally were characterized more rigorously prior to flight than were those in the LDEF systems, and thus post flight testing may yield more significant results.

Space environmental effects observed on the Hubble Space Telescope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edelman, J.E.; Mason, J.B.

1995-02-01

The Hubble Space Telescope (HST) Repair Mission of December, 1993, was first and foremost a mission to improve the performance of the observatory. But for a specialized segment of the aerospace industry, the primary interest is in the return to Earth of numerous pieces of the HST hardware, pieces which have been replaced, repaired, improved, or superseded. The returned hardware is of interest because of the information it potentially carries about the effects of exposure to the space environment for three and a half years. Like the LDEF retrieval mission four years ago, the HST repair mission is of interestmore » to many engineering disciplines, including all of the disciplines represented by the LDEF Special Investigation Groups (SIG`s). There is particular interest in the evaluation of specific materials and systems in the returned components. Some coated surfaces have been processed with materials which are newer and still in use by, or under consideration for, other spacecraft in a variety of stages of development. Several of the systems are being returned because a specific failure or anomaly has been observed and thus there is, at the outset, a specific investigative trail that needs to be followed. These systems are much more complex than those flown on LDEF and, in two instances, comprised state-of-the-art science instruments. Further, the parts used in these systems generally were characterized more rigorously prior to flight than were those in the LDEF systems, and thus post flight testing may yield more significant results.« less

On-board fault management for autonomous spacecraft

NASA Technical Reports Server (NTRS)

Fesq, Lorraine M.; Stephan, Amy; Doyle, Susan C.; Martin, Eric; Sellers, Suzanne

1991-01-01

The dynamic nature of the Cargo Transfer Vehicle's (CTV) mission and the high level of autonomy required mandate a complete fault management system capable of operating under uncertain conditions. Such a fault management system must take into account the current mission phase and the environment (including the target vehicle), as well as the CTV's state of health. This level of capability is beyond the scope of current on-board fault management systems. This presentation will discuss work in progress at TRW to apply artificial intelligence to the problem of on-board fault management. The goal of this work is to develop fault management systems. This presentation will discuss work in progress at TRW to apply artificial intelligence to the problem of on-board fault management. The goal of this work is to develop fault management systems that can meet the needs of spacecraft that have long-range autonomy requirements. We have implemented a model-based approach to fault detection and isolation that does not require explicit characterization of failures prior to launch. It is thus able to detect failures that were not considered in the failure and effects analysis. We have applied this technique to several different subsystems and tested our approach against both simulations and an electrical power system hardware testbed. We present findings from simulation and hardware tests which demonstrate the ability of our model-based system to detect and isolate failures, and describe our work in porting the Ada version of this system to a flight-qualified processor. We also discuss current research aimed at expanding our system to monitor the entire spacecraft.

A CLIPS based personal computer hardware diagnostic system

NASA Technical Reports Server (NTRS)

Whitson, George M.

1991-01-01

Often the person designated to repair personal computers has little or no knowledge of how to repair a computer. Described here is a simple expert system to aid these inexperienced repair people. The first component of the system leads the repair person through a number of simple system checks such as making sure that all cables are tight and that the dip switches are set correctly. The second component of the system assists the repair person in evaluating error codes generated by the computer. The final component of the system applies a large knowledge base to attempt to identify the component of the personal computer that is malfunctioning. We have implemented and tested our design with a full system to diagnose problems for an IBM compatible system based on the 8088 chip. In our tests, the inexperienced repair people found the system very useful in diagnosing hardware problems.

A Low Cost, Self Acting, Liquid Hydrogen Boil-Off Recovery System

NASA Technical Reports Server (NTRS)

Pelfrey, Joy W.; Sharp, Kirk V. (Technical Monitor)

2001-01-01

The purpose of this research was to develop a prototype liquid hydrogen boll-off recovery system. Perform analyses to finalize recovery system cycle, design detail components, fabricate hardware, and conduct sub-component, component, and system level tests leading to the delivery of a prototype system. The design point and off-design analyses identified cycle improvements to increase the robustness of the system by adding a by-pass heat exchanger. Based on the design, analysis, and testing conducted, the recovery system will liquefy 31% of the gaseous boil off from a liquid hydrogen storage tank. All components, including a high speed, miniature turbocompressor, were designed and manufacturing drawings were created. All hardware was fabricated and tests were conducted in air, helium, and hydrogen. Testing validated the design, except for the turbocompressor. A rotor-to-stator clearance issue was discovered as a result of a concentricity tolerance stack-up.

Methodology for the Incorporation of Passive Component Aging Modeling into the RAVEN/ RELAP-7 Environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mandelli, Diego; Rabiti, Cristian; Cogliati, Joshua

2014-11-01

Passive system, structure and components (SSCs) will degrade over their operation life and this degradation may cause to reduction in the safety margins of a nuclear power plant. In traditional probabilistic risk assessment (PRA) using the event-tree/fault-tree methodology, passive SSC failure rates are generally based on generic plant failure data and the true state of a specific plant is not reflected realistically. To address aging effects of passive SSCs in the traditional PRA methodology [1] does consider physics based models that account for the operating conditions in the plant, however, [1] does not include effects of surveillance/inspection. This paper representsmore » an overall methodology for the incorporation of aging modeling of passive components into the RAVEN/RELAP-7 environment which provides a framework for performing dynamic PRA. Dynamic PRA allows consideration of both epistemic and aleatory uncertainties (including those associated with maintenance activities) in a consistent phenomenological and probabilistic framework and is often needed when there is complex process/hardware/software/firmware/ human interaction [2]. Dynamic PRA has gained attention recently due to difficulties in the traditional PRA modeling of aging effects of passive components using physics based models and also in the modeling of digital instrumentation and control systems. RAVEN (Reactor Analysis and Virtual control Environment) [3] is a software package under development at the Idaho National Laboratory (INL) as an online control logic driver and post-processing tool. It is coupled to the plant transient code RELAP-7 (Reactor Excursion and Leak Analysis Program) also currently under development at INL [3], as well as RELAP 5 [4]. The overall methodology aims to: • Address multiple aging mechanisms involving large number of components in a computational feasible manner where sequencing of events is conditioned on the physical conditions predicted in a simulation environment such as RELAP-7. • Identify the risk-significant passive components, their failure modes and anticipated rates of degradation • Incorporate surveillance and maintenance activities and their effects into the plant state and into component aging progress. • Asses aging affects in a dynamic simulation environment 1. C. L. SMITH, V. N. SHAH, T. KAO, G. APOSTOLAKIS, “Incorporating Ageing Effects into Probabilistic Risk Assessment –A Feasibility Study Utilizing Reliability Physics Models,” NUREG/CR-5632, USNRC, (2001). 2. T. ALDEMIR, “A Survey of Dynamic Methodologies for Probabilistic Safety Assessment of Nuclear Power Plants, Annals of Nuclear Energy, 52, 113-124, (2013). 3. C. RABITI, A. ALFONSI, J. COGLIATI, D. MANDELLI and R. KINOSHITA “Reactor Analysis and Virtual Control Environment (RAVEN) FY12 Report,” INL/EXT-12-27351, (2012). 4. D. ANDERS et.al, "RELAP-7 Level 2 Milestone Report: Demonstration of a Steady State Single Phase PWR Simulation with RELAP-7," INL/EXT-12-25924, (2012).« less

Use of limited data to construct Bayesian networks for probabilistic risk assessment.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Groth, Katrina M.; Swiler, Laura Painton

2013-03-01

Probabilistic Risk Assessment (PRA) is a fundamental part of safety/quality assurance for nuclear power and nuclear weapons. Traditional PRA very effectively models complex hardware system risks using binary probabilistic models. However, traditional PRA models are not flexible enough to accommodate non-binary soft-causal factors, such as digital instrumentation&control, passive components, aging, common cause failure, and human errors. Bayesian Networks offer the opportunity to incorporate these risks into the PRA framework. This report describes the results of an early career LDRD project titled %E2%80%9CUse of Limited Data to Construct Bayesian Networks for Probabilistic Risk Assessment%E2%80%9D. The goal of the work was tomore » establish the capability to develop Bayesian Networks from sparse data, and to demonstrate this capability by producing a data-informed Bayesian Network for use in Human Reliability Analysis (HRA) as part of nuclear power plant Probabilistic Risk Assessment (PRA). This report summarizes the research goal and major products of the research.« less

Evaluate the application of modal test and analysis processes to structural fault detection in MSFC-STS project elements

NASA Technical Reports Server (NTRS)

Springer, William T.

1988-01-01

The Space Transportation System (STS) is a very complex and expensive flight system which is intended to carry payloads into low Earth orbit and return. A catastrophic failure of the STS (such as experienced in the 51-L incident) results in the loss of both human life as well as very expensive hardware. One impact of this incident was to reaffirm the need to do everything possible to insure the integrity and reliability of the STS is sufficient to produce a safe flight. One means of achieving this goal is to expand the number of inspection technologies available for use on the STS. The purpose was to begin to evaluate the possible use of assessing the structural integrity of STS components for which Marshall Space Flight Center (MSFC) has responsibility. This entailed reviewing the available literature and determining a low-level experimental program which could be performed by MSFC and would help establish the feasibility of using this technology for structural fault detection.

PhoneSat: Ground Testing of a Phone-Based Prototype Bus

NASA Technical Reports Server (NTRS)

Felix, Carmen; Howard, Benjamin; Reyes, Matthew; Snarskiy, Fedor; Hickman, Ryan; Boshuizen, Christopher; Marshall, William

2010-01-01

Most of the key capabilities that are requisite of a satellite bus are housed in today's smart phones. PhoneSat refers to an initiative to build a ground-based prototype vehicle that could all the basic functionality of a satellite, including attitude control, using a smart Phone as its central hardware. All components used were also low cost Commercial off the Shelf (COTS). In summer 2009, an initial prototype was created using the LEGO Mindstorm toolkit demonstrating simple attitude control. Here we report on a follow up initiative to design, build and test a vehicle based on the Google s smart phone Nexus One. The report includes results from initial thermal-vacuum chamber tests and low altitude sub-orbital rocket flights which show that, at least for short durations, the Nexus One phone is able to withstand key aspects of the space environment without failure. We compare the sensor data from the Phone's accelerometers and magnetometers with that of an external microelectronic inertial measurement unit.

Minimum Control Requirements for Advanced Life Support Systems

NASA Technical Reports Server (NTRS)

Boulange, Richard; Jones, Harry; Jones, Harry

2002-01-01

Advanced control technologies are not necessary for the safe, reliable and continuous operation of Advanced Life Support (ALS) systems. ALS systems can and are adequately controlled by simple, reliable, low-level methodologies and algorithms. The automation provided by advanced control technologies is claimed to decrease system mass and necessary crew time by reducing buffer size and minimizing crew involvement. In truth, these approaches increase control system complexity without clearly demonstrating an increase in reliability across the ALS system. Unless these systems are as reliable as the hardware they control, there is no savings to be had. A baseline ALS system is presented with the minimal control system required for its continuous safe reliable operation. This baseline control system uses simple algorithms and scheduling methodologies and relies on human intervention only in the event of failure of the redundant backup equipment. This ALS system architecture is designed for reliable operation, with minimal components and minimal control system complexity. The fundamental design precept followed is "If it isn't there, it can't fail".

75 FR 26841 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-12

... initiating a full service brake application in the event of a hardware or software failure that could impair the ability of the engineer to apply or release the brakes or; (ii) Access to direct manual control of... petition that the full service brake application is transmitted electronically to each MU's Friction Brake...

Hardware/Software To Support Distance Learning Classes.

ERIC Educational Resources Information Center

Harrison, Bruce, Jr.

While the major part of any class is the classroom contact time, out-of-class support often makes the difference between success and failure of a student. With distance learning classes, teachers are faced with a unique set of problems in supplying this outside support. Students are often spread over large geographical areas and have varying…

AADL and Model-based Engineering

DTIC Science & Technology

2014-10-20

and MBE Feiler, Oct 20, 2014 © 2014 Carnegie Mellon University We Rely on Software for Safe Aircraft Operation Embedded software systems ...D eveloper Compute Platform Runtime Architecture Application Software Embedded SW System Engineer Data Stream Characteristics Latency...confusion Hardware Engineer Why do system level failures still occur despite fault tolerance techniques being deployed in systems ? Embedded software

Lunar Landing Operational Risk Model

NASA Technical Reports Server (NTRS)

Mattenberger, Chris; Putney, Blake; Rust, Randy; Derkowski, Brian

2010-01-01

Characterizing the risk of spacecraft goes beyond simply modeling equipment reliability. Some portions of the mission require complex interactions between system elements that can lead to failure without an actual hardware fault. Landing risk is currently the least characterized aspect of the Altair lunar lander and appears to result from complex temporal interactions between pilot, sensors, surface characteristics and vehicle capabilities rather than hardware failures. The Lunar Landing Operational Risk Model (LLORM) seeks to provide rapid and flexible quantitative insight into the risks driving the landing event and to gauge sensitivities of the vehicle to changes in system configuration and mission operations. The LLORM takes a Monte Carlo based approach to estimate the operational risk of the Lunar Landing Event and calculates estimates of the risk of Loss of Mission (LOM) - Abort Required and is Successful, Loss of Crew (LOC) - Vehicle Crashes or Cannot Reach Orbit, and Success. The LLORM is meant to be used during the conceptual design phase to inform decision makers transparently of the reliability impacts of design decisions, to identify areas of the design which may require additional robustness, and to aid in the development and flow-down of requirements.

Multi-terabyte EIDE disk arrays running Linux RAID5

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanders, D.A.; Cremaldi, L.M.; Eschenburg, V.

2004-11-01

High-energy physics experiments are currently recording large amounts of data and in a few years will be recording prodigious quantities of data. New methods must be developed to handle this data and make analysis at universities possible. Grid Computing is one method; however, the data must be cached at the various Grid nodes. We examine some storage techniques that exploit recent developments in commodity hardware. Disk arrays using RAID level 5 (RAID-5) include both parity and striping. The striping improves access speed. The parity protects data in the event of a single disk failure, but not in the case ofmore » multiple disk failures. We report on tests of dual-processor Linux Software RAID-5 arrays and Hardware RAID-5 arrays using a 12-disk 3ware controller, in conjunction with 250 and 300 GB disks, for use in offline high-energy physics data analysis. The price of IDE disks is now less than $1/GB. These RAID-5 disk arrays can be scaled to sizes affordable to small institutions and used when fast random access at low cost is important.« less

The state agency experience (evaluation/selection of hardware for automated, geo-based information systems)

NASA Technical Reports Server (NTRS)

Campbell, L. F., Jr.

1981-01-01

The purpose and format of a panel session that addressed the procedures by which the hardware components of geographic information systems are evaluated and selected are described. State agencies from Alaska, Colorado, Montana, and Washington were represented and the topic was discussed within the general context of information requirements in land management decision making.

Space Telecommunications Radio Systems (STRS) Hardware Architecture Standard: Release 1.0 Hardware Section

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.; Kacpura, Thomas J.; Smith, Carl R.; Liebetreu, John; Hill, Gary; Mortensen, Dale J.; Andro, Monty; Scardelletti, Maximilian C.; Farrington, Allen

2008-01-01

This report defines a hardware architecture approach for software-defined radios to enable commonality among NASA space missions. The architecture accommodates a range of reconfigurable processing technologies including general-purpose processors, digital signal processors, field programmable gate arrays, and application-specific integrated circuits (ASICs) in addition to flexible and tunable radiofrequency front ends to satisfy varying mission requirements. The hardware architecture consists of modules, radio functions, and interfaces. The modules are a logical division of common radio functions that compose a typical communication radio. This report describes the architecture details, the module definitions, the typical functions on each module, and the module interfaces. Tradeoffs between component-based, custom architecture and a functional-based, open architecture are described. The architecture does not specify a physical implementation internally on each module, nor does the architecture mandate the standards or ratings of the hardware used to construct the radios.

Open-Source 3D-Printable Optics Equipment

PubMed Central

Zhang, Chenlong; Anzalone, Nicholas C.; Faria, Rodrigo P.; Pearce, Joshua M.

2013-01-01

Just as the power of the open-source design paradigm has driven down the cost of software to the point that it is accessible to most people, the rise of open-source hardware is poised to drive down the cost of doing experimental science to expand access to everyone. To assist in this aim, this paper introduces a library of open-source 3-D-printable optics components. This library operates as a flexible, low-cost public-domain tool set for developing both research and teaching optics hardware. First, the use of parametric open-source designs using an open-source computer aided design package is described to customize the optics hardware for any application. Second, details are provided on the use of open-source 3-D printers (additive layer manufacturing) to fabricate the primary mechanical components, which are then combined to construct complex optics-related devices. Third, the use of the open-source electronics prototyping platform are illustrated as control for optical experimental apparatuses. This study demonstrates an open-source optical library, which significantly reduces the costs associated with much optical equipment, while also enabling relatively easily adapted customizable designs. The cost reductions in general are over 97%, with some components representing only 1% of the current commercial investment for optical products of similar function. The results of this study make its clear that this method of scientific hardware development enables a much broader audience to participate in optical experimentation both as research and teaching platforms than previous proprietary methods. PMID:23544104

Open-source 3D-printable optics equipment.

PubMed

Zhang, Chenlong; Anzalone, Nicholas C; Faria, Rodrigo P; Pearce, Joshua M

2013-01-01

Just as the power of the open-source design paradigm has driven down the cost of software to the point that it is accessible to most people, the rise of open-source hardware is poised to drive down the cost of doing experimental science to expand access to everyone. To assist in this aim, this paper introduces a library of open-source 3-D-printable optics components. This library operates as a flexible, low-cost public-domain tool set for developing both research and teaching optics hardware. First, the use of parametric open-source designs using an open-source computer aided design package is described to customize the optics hardware for any application. Second, details are provided on the use of open-source 3-D printers (additive layer manufacturing) to fabricate the primary mechanical components, which are then combined to construct complex optics-related devices. Third, the use of the open-source electronics prototyping platform are illustrated as control for optical experimental apparatuses. This study demonstrates an open-source optical library, which significantly reduces the costs associated with much optical equipment, while also enabling relatively easily adapted customizable designs. The cost reductions in general are over 97%, with some components representing only 1% of the current commercial investment for optical products of similar function. The results of this study make its clear that this method of scientific hardware development enables a much broader audience to participate in optical experimentation both as research and teaching platforms than previous proprietary methods.

Integrated software health management for aerospace guidance, navigation, and control systems: A probabilistic reasoning approach

NASA Astrophysics Data System (ADS)

Mbaya, Timmy

Embedded Aerospace Systems have to perform safety and mission critical operations in a real-time environment where timing and functional correctness are extremely important. Guidance, Navigation, and Control (GN&C) systems substantially rely on complex software interfacing with hardware in real-time; any faults in software or hardware, or their interaction could result in fatal consequences. Integrated Software Health Management (ISWHM) provides an approach for detection and diagnosis of software failures while the software is in operation. The ISWHM approach is based on probabilistic modeling of software and hardware sensors using a Bayesian network. To meet memory and timing constraints of real-time embedded execution, the Bayesian network is compiled into an Arithmetic Circuit, which is used for on-line monitoring. This type of system monitoring, using an ISWHM, provides automated reasoning capabilities that compute diagnoses in a timely manner when failures occur. This reasoning capability enables time-critical mitigating decisions and relieves the human agent from the time-consuming and arduous task of foraging through a multitude of isolated---and often contradictory---diagnosis data. For the purpose of demonstrating the relevance of ISWHM, modeling and reasoning is performed on a simple simulated aerospace system running on a real-time operating system emulator, the OSEK/Trampoline platform. Models for a small satellite and an F-16 fighter jet GN&C (Guidance, Navigation, and Control) system have been implemented. Analysis of the ISWHM is then performed by injecting faults and analyzing the ISWHM's diagnoses.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daling, P.M.; Marler, J.E.; Vo, T.V.

This study evaluates the values (benefits) and impacts (costs) associated with potential resolutions to Generic Issue 143, ``Availability of HVAC and Chilled Water Systems.`` The study identifies vulnerabilities related to failures of HVAC, chilled water, and room cooling systems; develops estimates of room heatup rates and safety-related equipment vulnerabilities following losses of HVAC/room cooler systems; develops estimates of the core damage frequencies and public risks associated with failures of these systems; develops three proposed resolution strategies to this generic issue; and performs a value/impact analysis of the proposed resolutions. Existing probabilistic risk assessments for four representative plants, including one plantmore » from each vendor, form the basis for the core damage frequency and public risk calculations. Both internal and external events were considered. It was concluded that all three proposed resolution strategies exceed the $1,000/person-rem cost-effectiveness ratio. Additional evaluations were performed to develop ``generic`` insights on potential design-related and configuration-related vulnerabilities and potential high-frequency ({approximately}1E-04/RY) accident sequences that involve failures of HVAC/room cooling functions. It was concluded that, although high-frequency accident sequences may exist at some plants, these high-frequency sequences are plant-specific in nature or have been resolved through hardware and/or operational changes. The plant-specific Individual Plant Examinations are an effective vehicle for identification and resolution of these plant-specific anomalies and hardware configurations.« less

Galileo IOV Electrical Power Subsystem Relies On Li-Ion Batter Charge Management Controlled By Hardware

NASA Astrophysics Data System (ADS)

Douay, N.

2011-10-01

In the frame of GALILEO In-Orbit Validation program which is composed of 4 satellites, Thales Alenia Space France has designed, developed and tested the Electrical Power Subsystem. Besides some classical design choices like: -50V regulated main power bus provided by the PCDU manufactured by Terma (DK), -Solar array, manufactured by Dutch-Space (NL), using Ga-As triple junction technology from Azur Space Power Solar GmbH, -SAFT (FR) Lithium-ion Battery for which cell package balancing function is required, -Solar Array Drive Mechanism, provided by RUAG Space Switzerland, to transfer the power. This subsystem features a fully autonomous, failure tolerant, battery charge management able to operate even after a complete unavailability of the on-board software. The battery charge management is implemented such that priority is always given to satisfy the satellite main bus needs in order to maintain the main bus regulation under MEA control. This battery charge management principle provides very high reliability and operational robustness. So, the paper describes : -the battery charge management concept using a combination of PCDU hardware and relevant battery lines monitoring, -the functional aspect of the single point failure free S4R (Sequential Switching Shunt Switch Regulator) and associated performances, -the failure modes isolated and passivated by this architecture. The paper will address as well the autonomous balancing function characteristics and performances.

Core Community Specifications for Electron Microprobe Operating Systems: Software, Quality Control, and Data Management Issues

NASA Technical Reports Server (NTRS)

Fournelle, John; Carpenter, Paul

2006-01-01

Modem electron microprobe systems have become increasingly sophisticated. These systems utilize either UNIX or PC computer systems for measurement, automation, and data reduction. These systems have undergone major improvements in processing, storage, display, and communications, due to increased capabilities of hardware and software. Instrument specifications are typically utilized at the time of purchase and concentrate on hardware performance. The microanalysis community includes analysts, researchers, software developers, and manufacturers, who could benefit from exchange of ideas and the ultimate development of core community specifications (CCS) for hardware and software components of microprobe instrumentation and operating systems.

Distributed digital signal processors for multi-body structures

NASA Technical Reports Server (NTRS)

Lee, Gordon K.

1990-01-01

Several digital filter designs were investigated which may be used to process sensor data from large space structures and to design digital hardware to implement the distributed signal processing architecture. Several experimental tests articles are available at NASA Langley Research Center to evaluate these designs. A summary of some of the digital filter designs is presented, an evaluation of their characteristics relative to control design is discussed, and candidate hardware microcontroller/microcomputer components are given. Future activities include software evaluation of the digital filter designs and actual hardware inplementation of some of the signal processor algorithms on an experimental testbed at NASA Langley.

Microgravity Manufacturing

NASA Technical Reports Server (NTRS)

Cooper, Ken; Munafo, Paul M. (Technical Monitor)

2002-01-01

Manufacturing capability in outer space remains one of the critical milestones to surpass to allow humans to conduct long-duration manned space exploration. The high cost-to-orbit for leaving the Earth's gravitational field continues to be the limiting factor in carrying sufficient hardware to maintain extended life support in microgravity or on other planets. Additive manufacturing techniques, or 'chipless' fabrication, like RP are being considered as the most promising technologies for achieving in situ or remote processing of hardware components, as well as for the repair of existing hardware. At least three RP technologies are currently being explored for use in microgravity and extraterrestrial fabrication.

Extensible Hardware Architecture for Mobile Robots

NASA Technical Reports Server (NTRS)

Park, Eric; Kobayashi, Linda; Lee, Susan Y.

2005-01-01

The Intelligent Robotics Group at NASA Ames Research Center has developed a new mobile robot hardware architecture designed for extensibility and reconfigurability. Currently implemented on the k9 rover. and won to be integrated onto the K10 series of human-robot collaboration research robots, this architecture allows for rapid changes in instrumentation configuration and provides a high degree of modularity through a synergistic mix of off-the-shelf and custom designed components, allowing eased transplantation into a wide vane6 of mobile robot platforms. A component level overview of this architecture is presented along with a description of the changes required for implementation on K10 , followed by plans for future work.

Solid-State Lighting Module (SSLM)

NASA Technical Reports Server (NTRS)

2008-01-01

The project's goal was to build a light-emitting-diode (LED)-based light fixture that is identical in fit, form, and function to the existing International Space Station (ISS) General Luminaire Assembly (GLA) light fixture and fly it on the ISS in early FY 2008 as a Station Detailed Test Objective (SDTO). Our design offers the following strengths: proven component hardware: Our design uses components flown in other KSC-developed hardware; heat path thermal pad: LED array heat is transferred from the circuit board by silicon pad, negating the need for a cooling fan; variable colorimetry: The output light color can be changed by inserting different LED combinations.

Photovoltaic power conditioning subsystem: State of the art and development opportunities

NASA Technical Reports Server (NTRS)

Krauthamer, S.; Bahrami, K.; Das, R.; Macie, T.; Rippel, W.

1984-01-01

Photovoltaic systems, the state of the art of power conditioning subsystem components, and the design and operational interaction between photovoltaic systems and host utilities are detailed in this document. Major technical issues relating to the design and development of power conditioning systems for photovoltaic application are considered; these include: (1) standards, guidelines, and specifications; (2) cost effective hardware design; (3) impact of advanced components on power conditioning development; (4) protection and safety; (5) quality of power; (6) system efficiency; and (7) system integration with the host utility. Theories of harmonic distortion and reactive power flow are discussed, and information about power conditioner hardware and manufacturers is provided.

Crew Quarters (CQ) and Electromagnetic Interference (EMI) Measurement Facility Combined Impedance Study

NASA Technical Reports Server (NTRS)

Scully, Robert C.

2011-01-01

This report documents an investigation into observed failures associated with conducted susceptibility testing of Crew Quarters (CQ) hardware in the Johnson Space Center (JSC) Electromagnetic Interference (EMI) Measurement Facility, and the work accomplished to identify the source of the observed behavior. Investigation led to the conclusion that the hardware power input impedance was interacting with the facility power impedance leading to instability at the observed frequencies of susceptibility. Testing performed in other facilities did not show this same behavior, pointing back to the EMI Measurement Facility power as the potential root cause. A LISN emulating the Station power bus impedance was inserted into the power circuit, and the susceptibility was eliminated from the measurements.

Developing Sustainable Spacecraft Water Management Systems

NASA Technical Reports Server (NTRS)

Thomas, Evan A.; Klaus, David M.

2009-01-01

It is well recognized that water handling systems used in a spacecraft are prone to failure caused by biofouling and mineral scaling, which can clog mechanical systems and degrade the performance of capillary-based technologies. Long duration spaceflight applications, such as extended stays at a Lunar Outpost or during a Mars transit mission, will increasingly benefit from hardware that is generally more robust and operationally sustainable overtime. This paper presents potential design and testing considerations for improving the reliability of water handling technologies for exploration spacecraft. Our application of interest is to devise a spacecraft wastewater management system wherein fouling can be accommodated by design attributes of the management hardware, rather than implementing some means of preventing its occurrence.

DAME: planetary-prototype drilling automation.

PubMed

Glass, B; Cannon, H; Branson, M; Hanagud, S; Paulsen, G

2008-06-01

We describe results from the Drilling Automation for Mars Exploration (DAME) project, including those of the summer 2006 tests from an Arctic analog site. The drill hardware is a hardened, evolved version of the Advanced Deep Drill by Honeybee Robotics. DAME has developed diagnostic and executive software for hands-off surface operations of the evolved version of this drill. The DAME drill automation tested from 2004 through 2006 included adaptively controlled drilling operations and the downhole diagnosis of drilling faults. It also included dynamic recovery capabilities when unexpected failures or drilling conditions were discovered. DAME has developed and tested drill automation software and hardware under stressful operating conditions during its Arctic field testing campaigns at a Mars analog site.

Space Shuttle STS-1 SRB damage investigation

NASA Technical Reports Server (NTRS)

Nevins, C. D.

1982-01-01

The physical damage incurred by the solid rocket boosters during reentry on the initial space shuttle flight raised the question of whether the hardware, as designed, would yield the low cost per flight desired. The damage was quantified, the cause determined and specific design changes recommended which would preclude recurrence. Flight data, postflight analyses, and laboratory hardware examinations were used. The resultant findings pointed to two principal causes: failure of the aft skirt thermal curtain at the onset of reentry aerodynamic heating, and overloading of the aft shirt stiffening rings during water impact. Design changes were recommended on both the thermal curtain and the aft skirt structural members to prevent similar damage on future missions.

DAME: Planetary-Prototype Drilling Automation

NASA Astrophysics Data System (ADS)

Glass, B.; Cannon, H.; Branson, M.; Hanagud, S.; Paulsen, G.

2008-06-01

We describe results from the Drilling Automation for Mars Exploration (DAME) project, including those of the summer 2006 tests from an Arctic analog site. The drill hardware is a hardened, evolved version of the Advanced Deep Drill by Honeybee Robotics. DAME has developed diagnostic and executive software for hands-off surface operations of the evolved version of this drill. The DAME drill automation tested from 2004 through 2006 included adaptively controlled drilling operations and the downhole diagnosis of drilling faults. It also included dynamic recovery capabilities when unexpected failures or drilling conditions were discovered. DAME has developed and tested drill automation software and hardware under stressful operating conditions during its Arctic field testing campaigns at a Mars analog site.

Space Shuttle Upgrades Advanced Hydraulic Power System

NASA Technical Reports Server (NTRS)

2004-01-01

Three Auxiliary Power Units (APU) on the Space Shuttle Orbiter each provide 145 hp shaft power to a hydraulic pump which outputs 3000 psi hydraulic fluid to 41 hydraulic actuators. A hydrazine fuel powered APU utilized throughout the Shuttle program has undergone many improvements, but concerns remain with flight safety, operational cost, critical failure modes, and hydrazine related hazards. The advanced hydraulic power system (AHPS), also known as the electric APU, is being evaluated as an upgrade to replace the hydrazine APU. The AHPS replaces the high-speed turbine and hydrazine fuel supply system with a battery power supply and electric motor/pump that converts 300 volt electrical power to 3000 psi hydraulic power. AHPS upgrade benefits include elimination of toxic hydrazine propellant to improve flight safety, reduction in hazardous ground processing operations, and improved reliability. Development of this upgrade provides many interesting challenges and includes development of four hardware elements that comprise the AHPS system: Battery - The battery provides a high voltage supply of power using lithium ion cells. This is a large battery that must provide 28 kilowatt hours of energy over 99 minutes of operation at 300 volts with a peak power of 130 kilowatts for three seconds. High Voltage Power Distribution and Control (PD&C) - The PD&C distributes electric power from the battery to the EHDU. This 300 volt system includes wiring and components necessary to distribute power and provide fault current protection. Electro-Hydraulic Drive Unit (EHDU) - The EHDU converts electric input power to hydraulic output power. The EHDU must provide over 90 kilowatts of stable, output hydraulic power at 3000 psi with high efficiency and rapid response time. Cooling System - The cooling system provides thermal control of the Orbiter hydraulic fluid and EHDU electronic components. Symposium presentation will provide an overview of the AHPS upgrade, descriptions of the four hardware elements, and a summary of development results to date.

The Threat of Uncertainty: Why Using Traditional Approaches for Evaluating Spacecraft Reliability are Insufficient for Future Human Mars Missions

NASA Technical Reports Server (NTRS)

Stromgren, Chel; Goodliff, Kandyce; Cirillo, William; Owens, Andrew

2016-01-01

Through the Evolvable Mars Campaign (EMC) study, the National Aeronautics and Space Administration (NASA) continues to evaluate potential approaches for sending humans beyond low Earth orbit (LEO). A key aspect of these missions is the strategy that is employed to maintain and repair the spacecraft systems, ensuring that they continue to function and support the crew. Long duration missions beyond LEO present unique and severe maintainability challenges due to a variety of factors, including: limited to no opportunities for resupply, the distance from Earth, mass and volume constraints of spacecraft, high sensitivity of transportation element designs to variation in mass, the lack of abort opportunities to Earth, limited hardware heritage information, and the operation of human-rated systems in a radiation environment with little to no experience. The current approach to maintainability, as implemented on ISS, which includes a large number of spares pre-positioned on ISS, a larger supply sitting on Earth waiting to be flown to ISS, and an on demand delivery of logistics from Earth, is not feasible for future deep space human missions. For missions beyond LEO, significant modifications to the maintainability approach will be required.Through the EMC evaluations, several key findings related to the reliability and safety of the Mars spacecraft have been made. The nature of random and induced failures presents significant issues for deep space missions. Because spare parts cannot be flown as needed for Mars missions, all required spares must be flown with the mission or pre-positioned. These spares must cover all anticipated failure modes and provide a level of overall reliability and safety that is satisfactory for human missions. This will require a large amount of mass and volume be dedicated to storage and transport of spares for the mission. Further, there is, and will continue to be, a significant amount of uncertainty regarding failure rates for spacecraft components. This uncertainty makes it much more difficult to anticipate failures and will potentially require an even larger amount of spares to provide an acceptable level of safety. Ultimately, the approach to maintenance and repair applied to ISS, focusing on the supply of spare parts, may not be tenable for deep space missions. Other approaches, such as commonality of components, simplification of systems, and in-situ manufacturing will be required.

A Practical Application of Microcomputers to Control an Active Solar System.

ERIC Educational Resources Information Center

Goldman, David S.; Warren, William

1984-01-01

Describes the design and implementation of a microcomputer-based model active solar heating system. Includes discussions of: (1) the active solar components (solar collector, heat exchanger, pump, and fan necessary to provide forced air heating); (2) software components; and (3) hardware components (in the form of sensors and actuators). (JN)

Independent Orbiter Assessment (IOA): Assessment of the main propulsion subsystem FMEA/CIL, volume 3

NASA Technical Reports Server (NTRS)

Holden, K. A.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Main Propulsion System (MPS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to available data from the Rockwell Downey/NASA JSC FMEA/CIL review. Volume 3 continues the presentation of IOA worksheets and includes the potential critical items list.

On Using Commercial Off-the-Shelf (COTS) Electronic Products in Space

NASA Technical Reports Server (NTRS)

Culpepper, William X.

2002-01-01

NASA's Johnson Space Center (JSC) has utilized COTS products in its programs since the early 1990's. Recently it has become evident that, of all failure modes possible, radiation will probably dominate; sometimes to the point of driving system architecture. It is now imperative that radiation susceptibility be addressed when writing the system requirements. Susceptibility assessment, e.g. testing, must begin early in the design phase to establish performance and continue through the hardware qualification program to prove satisfaction of the original requirements(s). Examples of requirements, testing, and architecture versus failure rate will be given.

Redundancy management of inertial systems.

NASA Technical Reports Server (NTRS)

Mckern, R. A.; Musoff, H.

1973-01-01

The paper reviews developments in failure detection and isolation techniques applicable to gimballed and strapdown systems. It examines basic redundancy management goals of improved reliability, performance and logistic costs, and explores mechanizations available for both input and output data handling. The meaning of redundant system reliability in terms of available coverage, system MTBF, and mission time is presented and the practical hardware performance limitations of failure detection and isolation techniques are explored. Simulation results are presented illustrating implementation coverages attainable considering IMU performance models and mission detection threshold requirements. The implications of a complete GN&C redundancy management method on inertial techniques are also explored.

Advanced detection, isolation, and accommodation of sensor failures in turbofan engines: Real-time microcomputer implementation

NASA Technical Reports Server (NTRS)

Delaat, John C.; Merrill, Walter C.

1990-01-01

The objective of the Advanced Detection, Isolation, and Accommodation Program is to improve the overall demonstrated reliability of digital electronic control systems for turbine engines. For this purpose, an algorithm was developed which detects, isolates, and accommodates sensor failures by using analytical redundancy. The performance of this algorithm was evaluated on a real time engine simulation and was demonstrated on a full scale F100 turbofan engine. The real time implementation of the algorithm is described. The implementation used state-of-the-art microprocessor hardware and software, including parallel processing and high order language programming.

Man-rated flight software for the F-8 DFBW program

NASA Technical Reports Server (NTRS)

Bairnsfather, R. R.

1976-01-01

The design, implementation, and verification of the flight control software used in the F-8 DFBW program are discussed. Since the DFBW utilizes an Apollo computer and hardware, the procedures, controls, and basic management techniques employed are based on those developed for the Apollo software system. Program assembly control, simulator configuration control, erasable-memory load generation, change procedures and anomaly reporting are discussed. The primary verification tools are described, as well as the program test plans and their implementation on the various simulators. Failure effects analysis and the creation of special failure generating software for testing purposes are described.

Modeling Security Aspects of Network

NASA Astrophysics Data System (ADS)

Schoch, Elmar

With more and more widespread usage of computer systems and networks, dependability becomes a paramount requirement. Dependability typically denotes tolerance or protection against all kinds of failures, errors and faults. Sources of failures can basically be accidental, e.g., in case of hardware errors or software bugs, or intentional due to some kind of malicious behavior. These intentional, malicious actions are subject of security. A more complete overview on the relations between dependability and security can be found in [31]. In parallel to the increased use of technology, misuse also has grown significantly, requiring measures to deal with it.

Flight performance of Skylab attitude and pointing control system

NASA Technical Reports Server (NTRS)

Chubb, W. B.; Kennel, H. F.; Rupp, C. C.; Seltzer, S. M.

1975-01-01

The Skylab attitude and pointing control system (APCS) requirements are briefly reviewed and the way in which they became altered during the prelaunch phase of development is noted. The actual flight mission (including mission alterations during flight) is described. The serious hardware failures that occurred, beginning during ascent through the atmosphere, also are described. The APCS's ability to overcome these failures and meet mission changes are presented. The large around-the-clock support effort on the ground is discussed. Salient design points and software flexibility that should afford pertinent experience for future spacecraft attitude and pointing control system designs are included.

Mean PB To Failure - Initial results from a long-term study of disk storage patterns at the RACF

NASA Astrophysics Data System (ADS)

Caramarcu, C.; Hollowell, C.; Rao, T.; Strecker-Kellogg, W.; Wong, A.; Zaytsev, S. A.

2015-12-01

The RACF (RHIC-ATLAS Computing Facility) has operated a large, multi-purpose dedicated computing facility since the mid-1990’s, serving a worldwide, geographically diverse scientific community that is a major contributor to various HEPN projects. A central component of the RACF is the Linux-based worker node cluster that is used for both computing and data storage purposes. It currently has nearly 50,000 computing cores and over 23 PB of storage capacity distributed over 12,000+ (non-SSD) disk drives. The majority of the 12,000+ disk drives provide a cost-effective solution for dCache/XRootD-managed storage, and a key concern is the reliability of this solution over the lifetime of the hardware, particularly as the number of disk drives and the storage capacity of individual drives grow. We report initial results of a long-term study to measure lifetime PB read/written to disk drives in the worker node cluster. We discuss the historical disk drive mortality rate, disk drive manufacturers' published MPTF (Mean PB to Failure) data and how they are correlated to our results. The results help the RACF understand the productivity and reliability of its storage solutions and have implications for other highly-available storage systems (NFS, GPFS, CVMFS, etc) with large I/O requirements.

Automated Mixed Traffic Vehicle (AMTV) technology and safety study

NASA Technical Reports Server (NTRS)

Johnston, A. R.; Peng, T. K. C.; Vivian, H. C.; Wang, P. K.

1978-01-01

Technology and safety related to the implementation of an Automated Mixed Traffic Vehicle (AMTV) system are discussed. System concepts and technology status were reviewed and areas where further development is needed are identified. Failure and hazard modes were also analyzed and methods for prevention were suggested. The results presented are intended as a guide for further efforts in AMTV system design and technology development for both near term and long term applications. The AMTV systems discussed include a low speed system, and a hybrid system consisting of low speed sections and high speed sections operating in a semi-guideway. The safety analysis identified hazards that may arise in a properly functioning AMTV system, as well as hardware failure modes. Safety related failure modes were emphasized. A risk assessment was performed in order to create a priority order and significant hazards and failure modes were summarized. Corrective measures were proposed for each hazard.

Failure detection and fault management techniques for flush airdata sensing systems

NASA Technical Reports Server (NTRS)

Whitmore, Stephen A.; Moes, Timothy R.; Leondes, Cornelius T.

1992-01-01

Methods based on chi-squared analysis are presented for detecting system and individual-port failures in the high-angle-of-attack flush airdata sensing system on the NASA F-18 High Alpha Research Vehicle. The HI-FADS hardware is introduced, and the aerodynamic model describes measured pressure in terms of dynamic pressure, angle of attack, angle of sideslip, and static pressure. Chi-squared analysis is described in the presentation of the concept for failure detection and fault management which includes nominal, iteration, and fault-management modes. A matrix of pressure orifices arranged in concentric circles on the nose of the aircraft indicate the parameters which are applied to the regression algorithms. The sensing techniques are applied to the F-18 flight data, and two examples are given of the computed angle-of-attack time histories. The failure-detection and fault-management techniques permit the matrix to be multiply redundant, and the chi-squared analysis is shown to be useful in the detection of failures.

Software Reliability Analysis of NASA Space Flight Software: A Practical Experience

PubMed Central

Sukhwani, Harish; Alonso, Javier; Trivedi, Kishor S.; Mcginnis, Issac

2017-01-01

In this paper, we present the software reliability analysis of the flight software of a recently launched space mission. For our analysis, we use the defect reports collected during the flight software development. We find that this software was developed in multiple releases, each release spanning across all software life-cycle phases. We also find that the software releases were developed and tested for four different hardware platforms, spanning from off-the-shelf or emulation hardware to actual flight hardware. For releases that exhibit reliability growth or decay, we fit Software Reliability Growth Models (SRGM); otherwise we fit a distribution function. We find that most releases exhibit reliability growth, with Log-Logistic (NHPP) and S-Shaped (NHPP) as the best-fit SRGMs. For the releases that experience reliability decay, we investigate the causes for the same. We find that such releases were the first software releases to be tested on a new hardware platform, and hence they encountered major hardware integration issues. Also such releases seem to have been developed under time pressure in order to start testing on the new hardware platform sooner. Such releases exhibit poor reliability growth, and hence exhibit high predicted failure rate. Other problems include hardware specification changes and delivery delays from vendors. Thus, our analysis provides critical insights and inputs to the management to improve the software development process. As NASA has moved towards a product line engineering for its flight software development, software for future space missions will be developed in a similar manner and hence the analysis results for this mission can be considered as a baseline for future flight software missions. PMID:29278255

Software Reliability Analysis of NASA Space Flight Software: A Practical Experience.

PubMed

Sukhwani, Harish; Alonso, Javier; Trivedi, Kishor S; Mcginnis, Issac

2016-01-01

In this paper, we present the software reliability analysis of the flight software of a recently launched space mission. For our analysis, we use the defect reports collected during the flight software development. We find that this software was developed in multiple releases, each release spanning across all software life-cycle phases. We also find that the software releases were developed and tested for four different hardware platforms, spanning from off-the-shelf or emulation hardware to actual flight hardware. For releases that exhibit reliability growth or decay, we fit Software Reliability Growth Models (SRGM); otherwise we fit a distribution function. We find that most releases exhibit reliability growth, with Log-Logistic (NHPP) and S-Shaped (NHPP) as the best-fit SRGMs. For the releases that experience reliability decay, we investigate the causes for the same. We find that such releases were the first software releases to be tested on a new hardware platform, and hence they encountered major hardware integration issues. Also such releases seem to have been developed under time pressure in order to start testing on the new hardware platform sooner. Such releases exhibit poor reliability growth, and hence exhibit high predicted failure rate. Other problems include hardware specification changes and delivery delays from vendors. Thus, our analysis provides critical insights and inputs to the management to improve the software development process. As NASA has moved towards a product line engineering for its flight software development, software for future space missions will be developed in a similar manner and hence the analysis results for this mission can be considered as a baseline for future flight software missions.

Integral Sensor Fault Detection and Isolation for Railway Traction Drive.

PubMed

Garramiola, Fernando; Del Olmo, Jon; Poza, Javier; Madina, Patxi; Almandoz, Gaizka

2018-05-13

Due to the increasing importance of reliability and availability of electric traction drives in Railway applications, early detection of faults has become an important key for Railway traction drive manufacturers. Sensor faults are important sources of failures. Among the different fault diagnosis approaches, in this article an integral diagnosis strategy for sensors in traction drives is presented. Such strategy is composed of an observer-based approach for direct current (DC)-link voltage and catenary current sensors, a frequency analysis approach for motor current phase sensors and a hardware redundancy solution for speed sensors. None of them requires any hardware change requirement in the actual traction drive. All the fault detection and isolation approaches have been validated in a Hardware-in-the-loop platform comprising a Real Time Simulator and a commercial Traction Control Unit for a tram. In comparison to safety-critical systems in Aerospace applications, Railway applications do not need instantaneous detection, and the diagnosis is validated in a short time period for reliable decision. Combining the different approaches and existing hardware redundancy, an integral fault diagnosis solution is provided, to detect and isolate faults in all the sensors installed in the traction drive.

Integral Sensor Fault Detection and Isolation for Railway Traction Drive

PubMed Central

del Olmo, Jon; Poza, Javier; Madina, Patxi; Almandoz, Gaizka

2018-01-01

Due to the increasing importance of reliability and availability of electric traction drives in Railway applications, early detection of faults has become an important key for Railway traction drive manufacturers. Sensor faults are important sources of failures. Among the different fault diagnosis approaches, in this article an integral diagnosis strategy for sensors in traction drives is presented. Such strategy is composed of an observer-based approach for direct current (DC)-link voltage and catenary current sensors, a frequency analysis approach for motor current phase sensors and a hardware redundancy solution for speed sensors. None of them requires any hardware change requirement in the actual traction drive. All the fault detection and isolation approaches have been validated in a Hardware-in-the-loop platform comprising a Real Time Simulator and a commercial Traction Control Unit for a tram. In comparison to safety-critical systems in Aerospace applications, Railway applications do not need instantaneous detection, and the diagnosis is validated in a short time period for reliable decision. Combining the different approaches and existing hardware redundancy, an integral fault diagnosis solution is provided, to detect and isolate faults in all the sensors installed in the traction drive. PMID:29757251

Advanced Ground Systems Maintenance Prognostics Project

NASA Technical Reports Server (NTRS)

Harp, Janicce Leshay

2014-01-01

The project implements prognostics capabilities to predict when a component, system or subsystem will no longer meet desired functional or performance criteria, called the "end of life." The capability also provides an assessment of the "remaining useful life" of a hardware component.

Research on an autonomous vision-guided helicopter

NASA Technical Reports Server (NTRS)

Amidi, Omead; Mesaki, Yuji; Kanade, Takeo

1994-01-01

Integration of computer vision with on-board sensors to autonomously fly helicopters was researched. The key components developed were custom designed vision processing hardware and an indoor testbed. The custom designed hardware provided flexible integration of on-board sensors with real-time image processing resulting in a significant improvement in vision-based state estimation. The indoor testbed provided convenient calibrated experimentation in constructing real autonomous systems.

Communications Support for National Flight Data Center Information System.

DTIC Science & Technology

1980-11-01

funtions : 0 Establishment and termination, * Message transfer, 0 Retransmission of blocks, Establishment and Termination: the establishment procedure...relate to hardware components, transmission facilities and cost relationships . The costs are grouped into one-time and recurring costs. L.2 HARDWARE...the NADIN switching center in Atlanta. The purchase and installation costs are estimated to be $1000. L.4 COST RELATIONSHIPS In order to accurately

Failure and recovery in dynamical networks.

PubMed

Böttcher, L; Luković, M; Nagler, J; Havlin, S; Herrmann, H J

2017-02-03

Failure, damage spread and recovery crucially underlie many spatially embedded networked systems ranging from transportation structures to the human body. Here we study the interplay between spontaneous damage, induced failure and recovery in both embedded and non-embedded networks. In our model the network's components follow three realistic processes that capture these features: (i) spontaneous failure of a component independent of the neighborhood (internal failure), (ii) failure induced by failed neighboring nodes (external failure) and (iii) spontaneous recovery of a component. We identify a metastable domain in the global network phase diagram spanned by the model's control parameters where dramatic hysteresis effects and random switching between two coexisting states are observed. This dynamics depends on the characteristic link length of the embedded system. For the Euclidean lattice in particular, hysteresis and switching only occur in an extremely narrow region of the parameter space compared to random networks. We develop a unifying theory which links the dynamics of our model to contact processes. Our unifying framework may help to better understand controllability in spatially embedded and random networks where spontaneous recovery of components can mitigate spontaneous failure and damage spread in dynamical networks.

Virtually-synchronous communication based on a weak failure suspector

NASA Technical Reports Server (NTRS)

Schiper, Andre; Ricciardi, Aleta

1993-01-01

Failure detectors (or, more accurately Failure Suspectors (FS)) appear to be a fundamental service upon which to build fault-tolerant, distributed applications. This paper shows that a FS with very weak semantics (i.e., that delivers failure and recovery information in no specific order) suffices to implement virtually-synchronous communication (VSC) in an asynchronous system subject to process crash failures and network partitions. The VSC paradigm is particularly useful in asynchronous systems and greatly simplifies building fault-tolerant applications that mask failures by replicating processes. We suggest a three-component architecture to implement virtually-synchronous communication: (1) at the lowest level, the FS component; (2) on top of it, a component (2a) that defines new views; and (3) a component (2b) that reliably multicasts messages within a view. The issues covered in this paper also lead to a better understanding of the various membership service semantics proposed in recent literature.

Control system failure monitoring using generalized parity relations. M.S. Thesis Interim Technical Report

NASA Technical Reports Server (NTRS)

Vanschalkwyk, Christiaan Mauritz

1991-01-01

Many applications require that a control system must be tolerant to the failure of its components. This is especially true for large space-based systems that must work unattended and with long periods between maintenance. Fault tolerance can be obtained by detecting the failure of the control system component, determining which component has failed, and reconfiguring the system so that the failed component is isolated from the controller. Component failure detection experiments that were conducted on an experimental space structure, the NASA Langley Mini-Mast are presented. Two methodologies for failure detection and isolation (FDI) exist that do not require the specification of failure modes and are applicable to both actuators and sensors. These methods are known as the Failure Detection Filter and the method of Generalized Parity Relations. The latter method was applied to three different sensor types on the Mini-Mast. Failures were simulated in input-output data that were recorded during operation of the Mini-Mast. Both single and double sensor parity relations were tested and the effect of several design parameters on the performance of these relations is discussed. The detection of actuator failures is also treated. It is shown that in all the cases it is possible to identify the parity relations directly from input-output data. Frequency domain analysis is used to explain the behavior of the parity relations.