Theory and design of reliable spacecraft data systems Quarterly progress report, 10 May - 9 Aug. 1969
Theory and techniques for design, analysis, and fault diagnosis of reliable spacecraft data systems
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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System design of an outer planet spacecraft for long-life reliability
Spacecraft system design with long life reliability for outer planet exploration missions
Bowman, R. R.↗
An Integrated Fault Tolerant Robotic Controller System for High Reliability and Safety
This paper describes the concepts and features of a fault-tolerant intelligent robotic control system being developed for applications that require high dependability (reliability, availability, and safety). The system consists of two major elements: a fault-tolerant controller and an operator workstation. The fault-tolerant controller uses a strategy which allows for detection and recovery of hardware, operating system, and application software failures.The fault-tolerant controller can be used by itself in a wide variety of applications in industry, process control, and communications. The controller in combination with the operator workstation can be applied to robotic applications such as spaceborne extravehicular activities, hazardous materials handling, inspection and maintenance of high value items (e.g., space vehicles, reactor internals, or aircraft), medicine, and other tasks where a robot system failure poses a significant risk to life or property.
robotics fault-tolerant control systems↗
Trends in reliability modeling technology for fault tolerant systems
Developments in reliability modeling for large fault tolerant avionic computing systems are presented. Issues of state size and complexity, fault coverage, and practical computation are addressed. A two-fold developmental effort is described based on the structural and fault coverage modeling approaches. A technique which was successfully applied to an 865 state pure death stationary Markov model is presented. Of particular interest is a short computer program which executes very quickly to produce reliability results of a large state space model. This model also incorporates fault coverage states for processor, memory, and bus line replaceable units. A second structural reliability modeling scheme is aimed at solving nonstationary Markov models. This technique provides the tool required for studying the reliability of systems with nonconstant failure rates and includes intermittent/transient faults, electronic hardware which exhibits decreasing failure rates, and hydromechanical devices which typically have wearout failure mechanisms. Several aspects of fault coverage, including modeling and data measurement of intermittent/transient faults and latent faults, are elucidated and illustrated. The CARE II (computer-aided reliability estimation) coverage is presented and shortcomings to be eliminated are discussed.
Bavuso, S. J.↗
AST Critical Propulsion and Noise Reduction Technologies for Future Commercial Subsonic Engines Area of Interest 1.0: Reliable and Affordable Control Systems
The General Electric Reliable and Affordable Controls effort under the NASA Advanced Subsonic Technology (AST) Program has designed, fabricated, and tested advanced controls hardware and software to reduce emissions and improve engine safety and reliability. The original effort consisted of four elements: 1) a Hydraulic Multiplexer; 2) Active Combustor Control; 3) a Variable Displacement Vane Pump (VDVP); and 4) Intelligent Engine Control. The VDVP and Intelligent Engine Control elements were cancelled due to funding constraints and are reported here only to the state they progressed. The Hydraulic Multiplexing element developed and tested a prototype which improves reliability by combining the functionality of up to 16 solenoids and servo-valves into one component with a single electrically powered force motor. The Active Combustor Control element developed intelligent staging and control strategies for low emission combustors. This included development and tests of a Controlled Pressure Fuel Nozzle for fuel sequencing, a Fuel Multiplexer for individual fuel cup metering, and model-based control logic. Both the Hydraulic Multiplexer and Controlled Pressure Fuel Nozzle system were cleared for engine test. The Fuel Multiplexer was cleared for combustor rig test which must be followed by an engine test to achieve full maturation.
Myers, William↗
Reduction of control system design effort
Reliable control systems with satisfactory dynamic response for launch vehicles
Redus, J. R.↗
Reliable computation in computing systems designed from unreliable components.
Reliable computation in computing systems designed from unreliable components, considering two models for component malfunctions
Taylor, M. G.↗
Long life reliability thermal control systems study
The results of a program undertaken to conceptually design and evaluate a passive, high reliability, long life thermal control system for space station application are presented. The program consisted of four steps: (1) investigate and select potential thermal system elements; (2) conceive, evaluate and select a thermal control system using these elements; (3) conduct a verification test of a prototype segment of the selected system; and (4) evaluate the utilization of waste heat from the power supply. The result of this project is a conceptual thermal control system design which employs heat pipes as primary components, both for heat transport and temperature control. The system, its evaluation, and the test results are described.
Scollon, T. R., Jr.↗
Theory and design of reliable spacecraft data systems Quarterly progress report, 10 Feb. - 9 May 1970
Permanent memory fault analysis, faults in combinatorial networks, linear machines, and path sensitizing in network analysis for reliable spacecraft data systems
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A new approach to reliability estimation for reconfigurable systems
A new approach to computing the probability of failure for process-control systems that achieve reliability by redundancy and reconfiguration is described. This approach has three distinguishing characteristics. It is based on information about the components and the system that can be observed; it requires a minimum of information; and it fills the gaps by locating the redundant unit misbehavior pattern that produces the largest probability of system failure.
White, Allan L.↗
The B-747 flight control system maintenance and reliability data base for cost effectiveness tradeoff studies
Primary and automatic flight controls are combined for a total flight control reliability and maintenance cost data base using information from two previous reports and additional cost data gathered from a major airline. A comparison of the current B-747 flight control system effects on reliability and operating cost with that of a B-747 designed for an active control wing load alleviation system is provided.
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Development of reliability methodology for systems engineering. Volume I - Methodology - Analysis techniques and procedures Final report
Reliability analyses for equipment in design stage
QUALITY CONTROL↗
Toward Reaching a Consensus on the Concept of Power System Resilience: Definitions, Assessment Frameworks, and Metrics
Not Available
24 POWER TRANSMISSION AND DISTRIBUTION↗
Reliability studies of integrated modular engine system designs
A study was performed to evaluate the reliability of Integrated Modular Engine (IME) concepts. Comparisons were made between networked IME systems and non-networked discrete systems using expander cycle configurations. Both redundant and non-redundant systems were analyzed. Binomial approximation and Markov analysis techniques were employed to evaluate total system reliability. In addition, Failure Modes and Effects Analyses (FMEA), Preliminary Hazard Analyses (PHA), and Fault Tree Analysis (FTA) were performed to allow detailed evaluation of the IME concept. A discussion of these system reliability concepts is also presented.
Hardy, Terry L.↗
Reliability studies of Integrated Modular Engine system designs
A study was performed to evaluate the reliability of Integrated Modular Engine (IME) concepts. Comparisons were made between networked IME systems and non-networked discrete systems using expander cycle configurations. Both redundant and non-redundant systems were analyzed. Binomial approximation and Markov analysis techniques were employed to evaluate total system reliability. In addition, Failure Modes and Effects Analyses (FMEA), Preliminary Hazard Analyses (PHA), and Fault Tree Analysis (FTA) were performed to allow detailed evaluation of the IME concept. A discussion of these system reliability concepts is also presented.
Hardy, Terry L.↗
Approach to developing reliable space reactor power systems
During Phase II, the Engineering Development Phase, the SP-100 Project has defined and is pursuing a new approach to developing reliable power systems. The approach to developing such a system during the early technology phase is described along with some preliminary examples to help explain the approach. Developing reliable components to meet space reactor power system requirements is based on a top-down systems approach which includes a point design based on a detailed technical specification of a 100-kW power system. The SP-100 system requirements implicitly recognize the challenge of achieving a high system reliability for a ten-year lifetime, while at the same time using technologies that require very significant development efforts. A low-cost method for assessing reliability, based on an understanding of fundamental failure mechanisms and design margins for specific failure mechanisms, is being developed as part of the SP-100 Program.
Mondt, Jack F.↗
The implementation and use of Ada on distributed systems with high reliability requirements
The use and implementation of Ada in distributed environments in which reliability is the primary concern were investigted. A distributed system, programmed entirely in Ada, was studied to assess the use of individual tasks without concern for the processor used. Continued development and testing of the fault tolerant Ada testbed; development of suggested changes to Ada to cope with the failures of interest; design of approaches to fault tolerant software in real time systems, and the integration of these ideas into Ada; and the preparation of various papers and presentations were discussed.
Knight, J. C.↗
Rockwell Automation PLC-5 Lands Stennis Space Center with a Reliable, Flexible Control System
Ever since the first rocket was launched, people have been infatuated with the vast and unchartered frontier of space. Whether it's visiting a space center or watching a shuttle launch, people are waiting to see what will be discovered next. And even though orbiting the Earth or taking soil samples form the Moon now seems effortless, decades worth of behind-the-scenes work have helped the U.S. space program get to this point. Even today, NASA must take every precaution to ensure equipment is up to the endeavor of setting foot on the moon. As part of the initial push to put the first man on the moon, NASA established the John C. Stennis Space Center, Hancock County, Mississippi in 1961 for space engine propulsion system development. Today, Stennis has three major test complexes where engine and component testing is carried out and integrated into full motion systems for space shuttles and vehicles as well as secondary testing facilities. With different products being tested throughout the facilities, Stennis was in need of an automation system that could link the operations. By integrating a control system based on a Rockwell Automation's flexible and reliable PLC-5 controller, Stennis was able to implement projects more efficiently and focus its efforts on getting the next generation of products ready for space.
Epperson, Dave↗