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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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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1999

Safety Analysis of Soybean Processing for Advanced Life Support

Soybeans (cv. Hoyt) is one of the crops planned for food production within the Advanced Life Support System Integration Testbed (ALSSIT), a proposed habitat simulation for long duration lunar/Mars missions. Soybeans may be processed into a variety of food products, including soymilk, tofu, and tempeh. Due to the closed environmental system and importance of crew health maintenance, food safety is a primary concern on long duration space missions. Identification of the food safety hazards and critical control points associated with the closed ALSSIT system is essential for the development of safe food processing techniques and equipment. A Hazard Analysis Critical Control Point (HACCP) model was developed to reflect proposed production and processing protocols for ALSSIT soybeans. Soybean processing was placed in the type III risk category. During the processing of ALSSIT-grown soybeans, critical control points were identified to control microbiological hazards, particularly mycotoxins, and chemical hazards from antinutrients. Critical limits were suggested at each CCP. Food safety recommendations regarding the hazards and risks associated with growing, harvesting, and processing soybeans; biomass management; and use of multifunctional equipment were made in consideration of the limitations and restraints of the closed ALSSIT.

Hentges, Dawn L.↗
NASA NTRS2017

Cyber Safety and Security for Reduced Crew Operations (RCO)

NASA and the Aviation Industry is looking into reduced crew operations (RCO) that would cut today's required two-person flight crews down to a single pilot with support from ground-based crews. Shared responsibility across air and ground personnel will require highly reliable and secure data communication and supporting automation, which will be safety-critical for passenger and cargo aircraft. This paper looks at the different types and degrees of authority delegation given from the air to the ground and the ramifications of each, including the safety and security hazards introduced, the mitigation mechanisms for these hazards, and other demands on an RCO system architecture which would be highly invasive into (almost) all safety-critical avionics. The adjacent fields of unmanned aerial systems and autonomous ground vehicles are viewed to find problems that RCO may face and related aviation accident scenarios are described. The paper explores possible data communication architectures to meet stringent performance and information security (INFOSEC) requirements of RCO. Subsequently, potential challenges for RCO data communication authentication, encryption and non-repudiation are identified. The approach includes a comprehensive safety-hazard analysis of the RCO system to determine top level INFOSEC requirements for RCO and proposes an option for effective RCO implementation. This paper concludes with questioning the economic viability of RCO in light of the expense of overcoming the operational safety and security hazards it would introduce.

Aircraft Communication↗
NASA NTRS1991

Technical prospects for utilizing extraterrestrial propellants for space exploration

NASA's LeRC has supported several efforts to understand how lunar and Martian produced propellants can be used to their best advantage for space exploration propulsion. A discussion of these efforts and their results is presented. A Manned Mars Mission Analysis Study identified that a more thorough technology base for propellant production is required before the net economic benefits of in situ propellants can be determined. Evaluation of the materials available on the moon indicated metal/oxygen combinations are the most promising lunar propellants. A hazard analysis determined that several lunar metal/LOX monopropellants could be safely worked with in small quantities, and a characterization study was initiated to determine the physical and chemical properties of potential lunar monopropellant formulations. A bipropellant metal/oxygen subscale test engine which utilizes pneumatic injection of powdered metal is being pursued as an alternative to the monopropellant systems. The technology for utilizing carbon monoxide/oxygen, a potential Martian propellant, was studied in subscale ignition and rocket performance experiments.

Linne, Diane L.↗
NASA NTRS1991

Technical prospects for utilizing extraterrestrial propellants for space exploration

NASA's LeRC has supported several efforts to understand how lunar and Martian produced propellants can be used to their best advantage for space exploration propulsion. A discussion of these efforts and their results is presented. A Manned Mars Mission Analysis Study identified that a more thorough technology base for propellant production is required before the the net economic benefits of in situ propellants can be determined. Evaluation of the materials available on the moon indicated metal/oxygen combinations are the most promising lunar propellants. A hazard analysis determined that several lunar metal/LOX monopropellants could be safely worked with in small quantities, and a characterization study was initiated to determine the physical and chemical properties of potential lunar monopropellant formulations. A bipropellant metal/oxygen subscale test engine which utilizes pneumatic injection of powdered metal is being pursued as an alternative to the monopropellant systems. The technology for utilizing carbon monoxide/oxygen, a potential Martian propellant, was studied in subscale ignition and rocket performance experiments.

Linne, Diane L.↗
NASA NTRS2010

Risk Presentation Using the Three Dimensions of Likelihood, Severity, and Level of Control

Traditional hazard analysis techniques utilize a two-dimensional representation of the results determined by relative likelihood and severity of the residual risk. These matrices present a quick-look at the Likelihood (Y-axis) and Severity (X-axis) of the probable outcome of a hazardous event. A three-dimensional method, described herein, utilizes the traditional X and Y axes, while adding a new, third dimension, shown as the Z-axis, and referred to as the Level of Control. The elements of the Z-axis are modifications of the Hazard Elimination and Control steps (also known as the Hazard Reduction Precedence Sequence). These steps are: 1. Eliminate risk through design. 2. Substitute less risky materials for more hazardous materials. 3. Install safety devices. 4. Install caution and warning devices. 5. Develop administrative controls (to include special procedures and training.) 6. Provide protective clothing and equipment. When added to the two-dimensional models, the level of control adds a visual representation of the risk associated with the hazardous condition, creating a tall-pole for the leastwell-controlled failure while establishing the relative likelihood and severity of all causes and effects for an identified hazard. Computer modeling of the analytical results, using spreadsheets and three-dimensional charting gives a visual confirmation of the relationship between causes and their controls.

Watson, Clifford↗
NASA NTRS2010

Risk Assessment Using the Three Dimensions of Probability (Likelihood), Severity, and Level of Control

Traditional hazard analysis techniques utilize a two-dimensional representation of the results determined by relative likelihood and severity of the residual risk. These matrices present a quick-look at the Likelihood (Y-axis) and Severity (X-axis) of the probable outcome of a hazardous event. A three-dimensional method, described herein, utilizes the traditional X and Y axes, while adding a new, third dimension, shown as the Z-axis, and referred to as the Level of Control. The elements of the Z-axis are modifications of the Hazard Elimination and Control steps (also known as the Hazard Reduction Precedence Sequence). These steps are: 1. Eliminate risk through design. 2. Substitute less risky materials for more hazardous materials. 3. Install safety devices. 4. Install caution and warning devices. 5. Develop administrative controls (to include special procedures and training.) 6. Provide protective clothing and equipment. When added to the twodimensional models, the level of control adds a visual representation of the risk associated with the hazardous condition, creating a tall-pole for the least-well-controlled failure while establishing the relative likelihood and severity of all causes and effects for an identified hazard. Computer modeling of the analytical results, using spreadsheets and threedimensional charting gives a visual confirmation of the relationship between causes and their controls

Watson, Clifford↗
NASA NTRS2011

Risk Assessment Using the Three Dimensions of Probability (Likelihood), Severity, and Level of Control

Traditional hazard analysis techniques utilize a two-dimensional representation of the results determined by relative likelihood and severity of the residual risk. These matrices present a quick-look at the Likelihood (Y-axis) and Severity (X-axis) of the probable outcome of a hazardous event. A three-dimensional method, described herein, utilizes the traditional X and Y axes, while adding a new, third dimension, shown as the Z-axis, and referred to as the Level of Control. The elements of the Z-axis are modifications of the Hazard Elimination and Control steps (also known as the Hazard Reduction Precedence Sequence). These steps are: 1. Eliminate risk through design. 2. Substitute less risky materials for more hazardous materials. 3. Install safety devices. 4. Install caution and warning devices. 5. Develop administrative controls (to include special procedures and training.) 6. Provide protective clothing and equipment. When added to the two-dimensional models, the level of control adds a visual representation of the risk associated with the hazardous condition, creating a tall-pole for the least-well-controlled failure while establishing the relative likelihood and severity of all causes and effects for an identified hazard. Computer modeling of the analytical results, using spreadsheets and three-dimensional charting gives a visual confirmation of the relationship between causes and their controls.

Watson, Clifford C.↗
NASA NTRS2022

Preliminary Approach to Assess the Seismic Hazard on a Lunar Site

The passive seismic network deployed on the Moon during the Apollo missions operated for eight years and allowed the observation of seismic activity. More than 12500 seismic events were registered, where 28 were classified as shallow moonquakes with moment magnitudes up to 4.1. Seismic events of this nature pose a significant risk to future long-term lunar habitats; thus, these events must be carefully studied and considered in the seismic design of these structures. This paper proposes a preliminary seismic hazard assessment imposed by shallow moonquakes. The hazard assessment is performed using the Probabilistic Seismic Hazard Analysis (PSHA) methodology, considering previous studies and theories regarding the seismic environment of the Moon. The study zone covers ~860 km2 of the Taurus-Littrow Valley, containing the Apollo 17 landing site and the Lee-Lincoln lobate scarp as the considered seismic source. The seismic hazard is quantified in terms of peak ground acceleration (PGA) and spectral acceleration (5% damped pseudo-acceleration, PSA). Seismic hazard deaggregation scenarios, Uniform Hazard Spectra (UHS) for different hazard levels, and a Conditional Mean Spectrum (CMS) for a target period of 0.2 s are obtained to quantify the seismic hazard on a specific site on the Moon. The developed seismic hazard assessment provides a preliminary approach for realistic scenarios to conduct structural designs that ensure the seismic performance of fully operational long-term lunar structures.

Moonquake↗
NASA NTRS1978

Enclosure fire modeling

A fire characterization methodology is presented, which for the first time provides a unified analysis framework for the integration of all fire tests data on a common basis. Fire temperatures, smoke densities, toxic gas concentrations and heat fluxes to material properties, enclosure geometry, and ventilation factors are provided in this fire characterization approach. The fire characterization methodology was used to develop an enclosure fire hazards analysis procedure capable of predicting the probable course in fire prevention.

Coulbert, C. D.↗
NASA NTRS2012

Combining System Safety and Reliability to Ensure NASA CoNNeCT's Success

Hazard Analysis, Failure Modes and Effects Analysis (FMEA), the Limited-Life Items List (LLIL), and the Single Point Failure (SPF) List were applied by System Safety and Reliability engineers on NASA's Communications, Navigation, and Networking reConfigurable Testbed (CoNNeCT) Project. The integrated approach involving cross reviews of these reports by System Safety, Reliability, and Design engineers resulted in the mitigation of all identified hazards. The outcome was that the system met all the safety requirements it was required to meet.

Havenhill, Maria↗
NASA NTRS1971

Designing for auto safety

Safety design features in the motor vehicle and highway construction fields result from systems analysis approach to prevent or lessen death, injury, and property damage results. Systems analysis considers the prevention of crashes, increased survivability in crashes, and prompt medical attention to injuries as well as other postcrash salvage measures. The interface of these system elements with the driver, the vehicle, and the environment shows that action on the vehicle system produces the greatest safety payoff through design modifications. New and amended safety standards developed through hazard analysis technique improved accident statistics in the 70'; these regulations include driver qualifications and countermeasures to identify the chronic drunken driver who is involved in more than two-thirds of all auto deaths.

Elwood T. Driver↗
NASA NTRS2011

Probabilistic Risk Assessment Procedures Guide for NASA Managers and Practitioners (Second Edition)

Probabilistic Risk Assessment (PRA) is a comprehensive, structured, and logical analysis method aimed at identifying and assessing risks in complex technological systems for the purpose of cost-effectively improving their safety and performance. NASA's objective is to better understand and effectively manage risk, and thus more effectively ensure mission and programmatic success, and to achieve and maintain high safety standards at NASA. NASA intends to use risk assessment in its programs and projects to support optimal management decision making for the improvement of safety and program performance. In addition to using quantitative/probabilistic risk assessment to improve safety and enhance the safety decision process, NASA has incorporated quantitative risk assessment into its system safety assessment process, which until now has relied primarily on a qualitative representation of risk. Also, NASA has recently adopted the Risk-Informed Decision Making (RIDM) process [1-1] as a valuable addition to supplement existing deterministic and experience-based engineering methods and tools. Over the years, NASA has been a leader in most of the technologies it has employed in its programs. One would think that PRA should be no exception. In fact, it would be natural for NASA to be a leader in PRA because, as a technology pioneer, NASA uses risk assessment and management implicitly or explicitly on a daily basis. NASA has probabilistic safety requirements (thresholds and goals) for crew transportation system missions to the International Space Station (ISS) [1-2]. NASA intends to have probabilistic requirements for any new human spaceflight transportation system acquisition. Methods to perform risk and reliability assessment in the early 1960s originated in U.S. aerospace and missile programs. Fault tree analysis (FTA) is an example. It would have been a reasonable extrapolation to expect that NASA would also become the world leader in the application of PRA. That was, however, not to happen. Early in the Apollo program, estimates of the probability for a successful roundtrip human mission to the moon yielded disappointingly low (and suspect) values and NASA became discouraged from further performing quantitative risk analyses until some two decades later when the methods were more refined, rigorous, and repeatable. Instead, NASA decided to rely primarily on the Hazard Analysis (HA) and Failure Modes and Effects Analysis (FMEA) methods for system safety assessment.

Stamatelatos,Michael↗
NASA NTRS2011

NASA Accident Precursor Analysis Handbook, Version 1.0

Catastrophic accidents are usually preceded by precursory events that, although observable, are not recognized as harbingers of a tragedy until after the fact. In the nuclear industry, the Three Mile Island accident was preceded by at least two events portending the potential for severe consequences from an underappreciated causal mechanism. Anomalies whose failure mechanisms were integral to the losses of Space Transportation Systems (STS) Challenger and Columbia had been occurring within the STS fleet prior to those accidents. Both the Rogers Commission Report and the Columbia Accident Investigation Board report found that processes in place at the time did not respond to the prior anomalies in a way that shed light on their true risk implications. This includes the concern that, in the words of the NASA Aerospace Safety Advisory Panel (ASAP), "no process addresses the need to update a hazard analysis when anomalies occur" At a broader level, the ASAP noted in 2007 that NASA "could better gauge the likelihood of losses by developing leading indicators, rather than continue to depend on lagging indicators". These observations suggest a need to revalidate prior assumptions and conclusions of existing safety (and reliability) analyses, as well as to consider the potential for previously unrecognized accident scenarios, when unexpected or otherwise undesired behaviors of the system are observed. This need is also discussed in NASA's system safety handbook, which advocates a view of safety assurance as driving a program to take steps that are necessary to establish and maintain a valid and credible argument for the safety of its missions. It is the premise of this handbook that making cases for safety more experience-based allows NASA to be better informed about the safety performance of its systems, and will ultimately help it to manage safety in a more effective manner. The APA process described in this handbook provides a systematic means of analyzing candidate accident precursors by evaluating anomaly occurrences for their system safety implications and, through both analytical and deliberative methods used to project to other circumstances, identifying those that portend more serious consequences to come if effective corrective action is not taken. APA builds upon existing safety analysis processes currently in practice within NASA, leveraging their results to provide an improved understanding of overall system risk. As such, APA represents an important dimension of safety evaluation; as operational experience is acquired, precursor information is generated such that it can be fed back into system safety analyses to risk-inform safety improvements. Importantly, APA utilizes anomaly data to predict risk whereas standard reliability and PRA approaches utilize failure data which often is limited and rare.

Groen, Frank↗
NASA NTRSDate not supplied

Microgreens Food Safety Evaluation

Microgreens have been recently identified as a new type of pick and eat salad crop that can be utilized in space crop production systems. The majority of traditionally grown leafy green crops can be grown as microgreens, in addition to crops such as legumes (e.g. pea shoots), sunflower, buckwheat, most herbs, and corn, presenting hundreds of microgreen crop options. With a wide variety of flavors, exceptional nutritional density, short growth cycles (7-14 days), and unmatched volume optimization potential, microgreens present as an interesting option for sustainable production of nutritious and flavorful crops in space. The food safety aspects of microgreens have been investigated by USDA in recent years, however, an assessment for crew consumption purposes has not yet been conducted to capture the variety of microgreen cultivar types grown in spaceflight relevant environmental conditions and hardware that could be a part of the astronaut diet. Seed sanitation methods will be developed for each microgreen cultivar to sanitize the seed coat and ensure viable germination and plant growth. Food safety analysis will be performed on 24 different fast-growing cultivars of microgreens by performing aerobic plate counts (APC), fungal counts, and select pathogen screening of edible plant tissue before and after treatment with ProSan sanitizing produce wash. Additional avenues of investigation into microgreens food safety will be undertaken to understand impacts of plant height at time of harvest (able to be manipulated by light spectrum), seed density at time of planting, and role of blue light in food safety metrics of microgreens (n=6-12 microgreen cultivars tested, depending on variable). These findings will be included in the Space Crop Production Hazard Analysis Critical Control Point (HACCP) plan. This new work is currently postponed due to Covid-19.

M E Hummerick↗
NASA NTRS2014

Automated Standard Hazard Tool

The current system used to generate standard hazard reports is considered cumbersome and iterative. This study defines a structure for this system's process in a clear, algorithmic way so that standard hazard reports and basic hazard analysis may be completed using a centralized, web-based computer application. To accomplish this task, a test server is used to host a prototype of the tool during development. The prototype is configured to easily integrate into NASA's current server systems with minimal alteration. Additionally, the tool is easily updated and provides NASA with a system that may grow to accommodate future requirements and possibly, different applications. Results of this project's success are outlined in positive, subjective reviews complete by payload providers and NASA Safety and Mission Assurance personnel. Ideally, this prototype will increase interest in the concept of standard hazard automation and lead to the full-scale production of a user-ready application.

Stebler, Shane↗
NASA NTRS2002

Flight Evaluation of the Army/NASA Variable Stability Fly-by-Wire Rotorcraft Aircrew Systems Concept Airborne Laboratory (RASCAL) JUH-60A

NASA Ames Research Center and the U.S. Army Aeroflight dynamics Directorate (AFDD) have performed initial flight evaluations of the Research Flight Control System (RFCS) integrated into the Army/NASA Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) JUH-GOA. The highly modified JUH-GOA Black Hawk helicopter is a full authority, high bandwidth, variable stability, in-flight simulator designed to support development of advanced flight control, sensor, and integrated display and control technologies in a fail safe environment. Preparation for flight test required an extensive hazard analysis and ground testing to ensure proper system operation. A hardware in the loop development facility was utilized to evaluate control law stability following software changes, assess servo hardover upset conditions during manual and monitor disengagements and provide pilot familiarization of test techniques and software changes prior to flight. First engagement of the RFCS was conducted on 31 Aug 2001. RFCS transfer system operation, envelope expansion and a limited rate monitor evaluation have been completed with low bandwidth and model following control laws. The presentation will discuss the following - System overview including aircraft modifications and integrated development facilities used with the RASCAL facility. - Preliminary hazard identification and mitigation prior to flight test. - Ground testing used to qualify the RFCS transfer system and verify fault monitor operation. - Flight test results of low-bandwidth and model following control law evaluations including maneuver agility, control limitations, fault monitor reliability, and recovery from manual and monitor disengagement. - Lessons learned including test techniques using a passive three-axis sidearm controller, the value of the development facility in reducing risk and crew coordination issues related to the operation of a full authority, variable stability platform. - Future research and modifications planned for the RASCAL aircraft.

Dave Arterburn↗
NASA NTRSDate not supplied

Defining Collaborative Control Interactions Using Systems Theory

Human teams collaborate by establishing roles, changing functional authorities, maintaining team cognition, coordinating, and mutually helping one another close control loops. These complex inter-actions are inspiring novel concepts to improve human-machine and multi-machine collaboration. However, these new systems face engineering gaps in modeling, analysis, design, and assurance. As such, few have been fielded in safety-critical domains like aerospace. To analyze safety, this paper introduces a system-theoretic framework to describe interactions that are—or are planned to be—used in multi-controller systems. It outlines a taxonomy of seven structural dimensions that influence controller interactions and nine dynamics observed in collaborative control that are defined using Systems Theory. An analyzed set of 101 controller interactions in aerospace systems demonstrates how to apply the framework and that designers are trying to create more sophisticated systems. This framework provides the foundation to extend system-theoretic hazard analysis techniques to systematically find collabora-tive-control causal factors.

Human machine teaming↗
NASA NTRS2011

The Necessity of Functional Analysis for Space Exploration Programs

As NASA moves toward expanded commercial spaceflight within its human exploration capability, there is increased emphasis on how to allocate responsibilities between government and commercial organizations to achieve coordinated program objectives. The practice of program-level functional analysis offers an opportunity for improved understanding of collaborative functions among heterogeneous partners. Functional analysis is contrasted with the physical analysis more commonly done at the program level, and is shown to provide theoretical performance, risk, and safety advantages beneficial to a government-commercial partnership. Performance advantages include faster convergence to acceptable system solutions; discovery of superior solutions with higher commonality, greater simplicity and greater parallelism by substituting functional for physical redundancy to achieve robustness and safety goals; and greater organizational cohesion around program objectives. Risk advantages include avoidance of rework by revelation of some kinds of architectural and contractual mismatches before systems are specified, designed, constructed, or integrated; avoidance of cost and schedule growth by more complete and precise specifications of cost and schedule estimates; and higher likelihood of successful integration on the first try. Safety advantages include effective delineation of must-work and must-not-work functions for integrated hazard analysis, the ability to formally demonstrate completeness of safety analyses, and provably correct logic for certification of flight readiness. The key mechanism for realizing these benefits is the development of an inter-functional architecture at the program level, which reveals relationships between top-level system requirements that would otherwise be invisible using only a physical architecture. This paper describes the advantages and pitfalls of functional analysis as a means of coordinating the actions of large heterogeneous organizations for space exploration programs.

program management↗