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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 613 records · Page 34

All sources NASA NTRS DOE OSTI

NASA NTRS1981

Reliability and quality assurance on the MOD 2 wind system

The Safety, Reliability, and Quality Assurance (R&QA) approach developed for the largest wind turbine generator, the Mod 2, is described. The R&QA approach assures that the machine is not hazardous to the public or to the operating personnel, is operated unattended on a utility grid, demonstrates reliable operation, and helps establish the quality assurance and maintainability requirements for future wind turbine projects. The significant guideline consisted of a failure modes and effects analysis (FMEA) during the design phase, hardware inspections during parts fabrication, and three simple documents to control activities during machine construction and operation.

Mason, W. E. B.↗

NASA NTRS1982

Experience with modified aerospace reliability and quality assurance method for wind turbines

The SR&QA approach assures that the machine is not hazardous to the public or operating personnel, can operate unattended on a utility grid, demonstrates reliability operation, and helps establish the quality assurance and maintainability requirements for future wind turbine projects. The approach consisted of modified failure modes and effects analysis (FMEA) during the design phase, minimal hardware inspection during parts fabrication, and three simple documents to control activities during machine construction and operation. Five years experience shows that this low cost approach works well enough that it should be considered by others for similar projects.

Klein, W. E.↗

NASA NTRS1994

An algorithm for the Italian atomic time scale

During the past twenty years, the time scale at the IEN has been realized by a commercial cesium clock, selected from an ensemble of five, whose rate has been continuously steered towards UTC to maintain a long term agreement within 3 x 10(exp -13). A time scale algorithm, suitable for a small clock ensemble and capable of improving the medium and long term stability of the IEN time scale, has been recently designed taking care of reducing the effects of the seasonal variations and the sudden frequency anomalies of the single cesium clocks. The new time scale, TA(IEN), is obtained as a weighted average of the clock ensemble computed once a day from the time comparisons between the local reference UTC(IEN) and the single clocks. It is foreseen to include in the computation also ten cesium clocks maintained in other Italian laboratories to further improve its reliability and its long term stability. To implement this algorithm, a personal computer program in Quick Basic has been prepared and it has been tested at the IEN time and frequency laboratory. Results obtained using this algorithm on the real clocks data relative to a period of about two years are presented.

Cordara, F.↗

NASA NTRS1993

The methodology of multi-viewpoint clustering analysis

One of the greatest challenges facing the software engineering community is the ability to produce large and complex computer systems, such as ground support systems for unmanned scientific missions, that are reliable and cost effective. In order to build and maintain these systems, it is important that the knowledge in the system be suitably abstracted, structured, and otherwise clustered in a manner which facilitates its understanding, manipulation, testing, and utilization. Development of complex mission-critical systems will require the ability to abstract overall concepts in the system at various levels of detail and to consider the system from different points of view. Multi-ViewPoint - Clustering Analysis MVP-CA methodology has been developed to provide multiple views of large, complicated systems. MVP-CA provides an ability to discover significant structures by providing an automated mechanism to structure both hierarchically (from detail to abstract) and orthogonally (from different perspectives). We propose to integrate MVP/CA into an overall software engineering life cycle to support the development and evolution of complex mission critical systems.

Mehrotra, Mala↗

NASA NTRSDate not supplied

The Plant Water Management Experiments: Hydroponics 3 & 4

As humans consider longer-duration missions in space, NASA has identified production of fresh vegetables aboard spacecraft as beneficial for crew nutrition, mental wellbeing, and enabling bioregenerative life support (i.e., air, water, and waste processing). Current low-g plant growth techniques have successfully grown a variety of leafy and flowering plants. However, unique microgravity fluidics challenges to maintain plant moisture levels persist which hamper overall system reliability. The Plant Water Management (PWM) experiments seek to demonstrate low-cost, low-mass, reusable plant growth systems that leverage recent advances in low-g capillary fluidics phenomena to provide routine, largely passive, water delivery to plants. This paper presents findings from a series of PWM-Hydroponics 3 & 4 experiments, which were collected during three ISS flight operations that occurred in March, May, and July of 2021. Open hydroponic capillary channel flows with synthetic evapo-transpiring plant models were used. Tests demonstrated flow stability for single and parallel channel flow configurations across a range of flow rates, plant types, and plant arrangements. Technology demonstrations of both passive aeration and bubble phase separation are reported. We provide details of the data reduction and archive. Insights from the successful flight demonstrations provide a foundation from which follow-on PWM-Hydroponics 5 & 6 experiments on ISS, potentially incorporate living plants, are being considered. Xx Summary of positives and negatives..

Marc B. Wasserman↗

DOE OSTI2024

Data Analytics and Visualization of Energy Systems for Critical Infrastructure Insights

Modernization of energy systems including transportation facilities provides opportunities for increased efficiency, expansion of commerce and meeting industry and federal goals. A significant increase in electrical demand is projected to meet these needs, which concentrates at facilities such as airports. For example, Xcel Energy working with two airports in their service area recently published information projecting an up to fivefold increase in electricity demand in the next 25 years [1]. Concurrently, the US Government Accountability Office (GAO) recently surveyed 30 commercial service airports identifying more than 300 outages of more than 5 minutes between 2015 and 2022 [2]. Power, reliability, and resilience planning becomes more important to safely maintain operations and the flow of commerce with fewer energy carriers providing necessary energy to safely move passengers and goods. NREL proposes to develop methodologies to allow owners, utilities, and federal agencies to dynamically analyze, forecast, and manage energy loads at airports, focused upon maintaining the flow of commerce in an efficient, sustainable, and resilient way. To address these energy challenges, a suite of technologies and methodologies can be leveraged to validate concepts, inform design, de-risk solutions and optimize energy management during deployment. These technologies include digitalization of energy systems, microgrid methodologies, and related energy technologies for building and vehicle loads. [1] Electrifying Airport Ecosystems - https://www.enterprisemobility.com/content/dam/enterpriseholdings/marketing/innovation-in-mobility/vehicle-innovation/airport-electrification-study-full-report-2024.pdf [2] Airport Infrastructure: Selected Airport's Efforts to Enhance Electrical Resilience https://www.gao.gov/products/gao-23-105203.

critcal infrastructure↗

NASA NTRS2004

Reliability Assessment Approach for Stirling Convertors and Generators

Stirling power conversion is being considered for use in a Radioisotope Power System for deep-space science missions because it offers a multifold increase in the conversion efficiency of heat to electric power. Quantifying the reliability of a Radioisotope Power System that utilizes Stirling power conversion technology is important in developing and demonstrating the capability for long-term success. A description of the Stirling power convertor is provided, along with a discussion about some of the key components. Ongoing efforts to understand component life, design variables at the component and system levels, related sources, and the nature of uncertainties is discussed. The requirement for reliability also is discussed, and some of the critical areas of concern are identified. A section on the objectives of the performance model development and a computation of reliability is included to highlight the goals of this effort. Also, a viable physics-based reliability plan to model the design-level variable uncertainties at the component and system levels is outlined, and potential benefits are elucidated. The plan involves the interaction of different disciplines, maintaining the physical and probabilistic correlations at all the levels, and a verification process based on rational short-term tests. In addition, both top-down and bottom-up coherency were maintained to follow the physics-based design process and mission requirements. The outlined reliability assessment approach provides guidelines to improve the design and identifies governing variables to achieve high reliability in the Stirling Radioisotope Generator design.

Shah, Ashwin R.↗

NASA NTRS2016

The Threat of Uncertainty: Why Using Traditional Approaches for Evaluating Spacecraft Reliability are Insufficient for Future Human Mars Missions

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.

Stromgren, Chel↗

DOE OSTI2024

Reconfigurable Network Slicing Orchestration in Network Function Virtualization Compatible Operational Technology Environment

The ongoing transition to Industry 4.0, which is characterized by increased inter-connectivity of cyber-physical systems, requires having time-sensitive, high throughput, and secure transfer of critical data in industrial sites. In this context, network slicing emerges as a critical tool to ensure timely data delivery by provisioning the network resources to cater to specific applications’ requirements and mitigating potential cyber attacks. To address these challenges, this paper aims to tackle two key questions essential for the successful implementation of network slicing in industrial environments. First, it investigates architectural considerations for developing a network infrastructure capable of supporting network slicing functionalities effectively. The proposed approach significantly improves deployment efficiency over traditional manual configurations. Second, it delves into the automated orchestration process, elucidating the steps and components involved in transitioning from a static network management approach to dynamically leverage network function virtualization schemes for creating network slices in ad-hoc manner. The system demonstrates high throughput suitable for production-level solutions and maintains exceptionally low latency, making it ideal for ultra-reliable low-latency communications. Even with increased network demands, the system remains stable, with effective Quality of Service (QoS) management, ensuring reliable performance under varying conditions. The proposed architecture outlines the necessary components, services, and communication protocols required for a production-level orchestrator for network segmentation in SCADA environments.

Rodiles Delgado, Brian G.↗

NASA NTRS1980

An improved welding-arc starter

Simple circuit modification makes pulse-arc starters more reliable at low currents. Once arc is started, it is maintained at lower voltage level that in previous arrangement due to sufficient concentration of metallic vapor between electrode and working surface as result of improved conduction.

Taufer, T. J.↗

NASA NTRS1980

Modified aerospace reliability and quality assurance method for wind turbines

The safety, reliability, and quality assurance (SR&QA) approach developed for the first large wind turbine generator project is described. The SR&QA approach was used to assure that the machine would not be hazardous to the public or operating personnel, would operate unattended on a utility grid, would demonstrate reliable operation and would help establish the quality assurance and maintainability requirements for future wind turbine projects. A modified failure modes and effects analysis during the design phase, minimal hardware inspections during parts fabrication, and three simple documents to control activities during machine construction and operation were presented.

Klein, W. E.↗

NASA NTRS1980

Modified aerospace R&QA method for wind turbines

This paper describes the Safety, Reliability and Quality Assurance (SR&QA) approach developed for the first large wind turbine generator project, MOD-OA. The SR&QA approach to be used had to assure that the machine would not be hazardous, would operate unattended on a utility grid, would demonstrate reliable operation, and would help establish the quality assurance and maintainability requirements for wind turbine projects. The final approach consisted of a modified Failure Modes and Effects Analysis (FMEA) during the design phase, minimal hardware inspections during parts fabrication, and three documents to control activities during machine construction and operation.

Klein, W. E.↗

NASA NTRS2003

NASA's Next Generation Launch Technology Program - Strategy and Plans

The National Aeronautics and Space Administration established a new program office, Next Generation Launch Technology (NGLT) Program Office, last year to pursue technologies for future space launch systems. NGLT will fund research in key technology areas such as propulsion, launch vehicles, operations and system analyses. NGLT is part of NASA s Integrated Space Technology Plan. The NGLT Program is sponsored by NASA s Office of Aerospace Technology and is part of the Space Launch Initiative theme that includes both NGLT and Orbital Space Plane. NGLT will focus on technology development to increase safety and reliability and reduce overall costs associated with building, flying and maintaining the nation s next-generations of space launch vehicles. These investments will be guided by systems engineering and analysis with a focus on the needs of National customers.

Hueter, Uwe↗

NASA NTRS2018

Prognostics As-A-Service (PaaS)

Deep awareness of aircraft system health-state is critical for maintaining safe, efficient growth in global operations and enabling autonomy. Maintainers, operators, controllers, dispatchers, pilots, and autonomous systems must have reliable real-time predictions of vehicle health to preserve safety and efficiency. We will explore the feasibility and challenges of cloud enhanced prognostics. Aircraft request PaaS in flight to supplement onboard systems or provide complete health awareness. We will explore and demonstrate the ability to address six major challenges of PaaS: Generality, Environmental Complexity, Utility, Trust, Communications, and Security. We will also explore the factors in the decision to host prognostics onboard vs As-A-Service.

Prognostics As A Service↗

NASA NTRSDate not supplied

Comparison of Exploration Oxygen Recovery Technology Options Using ESM and LSMAC

In preparation for long duration manned space flight, numerous technology development efforts are ongoing in the area of environmental control and life support (ECLS). In cooperation with international, industry, and academic partners, NASA seeks to leverage the International Space Station as a testbed for technologies targeted for Exploration-class missions. In recent years, Equivalent Systems Mass (ESM) analyses have been conducted to evaluate the relative breakeven points and to compare technologies as part of ECLS architectural trades. While these studies have provided important data pertaining to key engineering metrics, additional considerations are important to more fully understand the potential impacts and costs associated with selecting a specific architecture. A tool, called the Life Support Multi-Dimensional Assessment Criteria (LSMAC), was recently proposed by Sierra Nevada Corporation in an attempt to incorporate influences of these additional considerations including Maintainability, Risk Analysis, Technology Readiness Level, Radiation Impacts, Manufacturing Costs, Reliability, Human Factors, and Un-Crewed Operations. As a first step toward evaluating and implementing this tool, LSMAC was used to revisit the ISS oxygen recovery trade from the 1990’s wherein Sabatier was selected over Bosch technology. Second, the tool was used to compare oxygen recovery developmental technologies currently in work. The results of these studies as well as a comparison with standalone ESM analyses are reported. Further, a discussion of the potential application of the tool across the ECLS portfolio and its potential use in future technology selection for ISS flight demonstrations is provided.

Morgan B Abney↗

NASA NTRSDate not supplied

DEVELOPING AN EARTH-FIXED VISUAL REFERENCE TO AID STABILITY, READAPTATION, AND EGRESS AFTER A WATER LANDING

Water landings present the worst possible sensory conditions for crews trying to orient and stabilize themselves immediately after long-duration spaceflight. Of the three sensory feedback systems involved in maintaining stability (i.e., proprioceptive, vestibular, and visual), none will provide reliable orientation information under the current water landing scenarios. Although the visual system is likely not affected by the disuse and adaptation to microgravity that affect the proprioceptive and vestibular systems, the visual environment within an enclosed space that is subject to wave-induced rocking will prevent the crewmember from using vision to determine which direction is up. This is true whether enclosed in the capsule or in a room on the recovery ship. The result is an increased risk of fall-related injury. In a prior study, 70% (21 of 30) of nonimpaired subjects reported that the presence of an Earth-fixed horizontal line helped them stabilize when their visually enclosed environment was exposed to wave motion. In addition to aiding stability, an Earth-fixed visual reference also can assist in the readaptation process. Sensory re-adaptation occurs when the three sensory systems are synchronized with one another and aligned with Earth’s gravity. The earlier an Earth-fixed visual reference can be introduced the sooner the readaptation process can begin. The goal of this project is to identify the optimal features of a device that visually presents gravitational reference cues to support egress, stability and readaptation. **Remainder of abstract in document preview or downloadable version

B. T. Peters↗

NASA NTRSDate not supplied

Developing An Earth-Fixed Visual Reference to Aid Stability, Readaptation and Egress After a Water Landing

INTRODUCTION Water landings present the worst possible sensory conditions for crews trying to orient and stabilize themselves immediately after long-duration spaceflight. Of the three sensory feedback systems involved in maintaining stability (i.e., proprioceptive, vestibular, and visual), none will provide reliable orientation information under the current water landing scenarios. The proprioceptive and vestibular systems are affected during spaceflight by disuse and adaptation to microgravity. Vision may not suffer the same degradation, but the visual environment within the enclosed space of a capsule, or interior room of a recovery ship, is disorienting when subject to wave-induced motion. The result is an increased risk of fall-related injury. In a prior study, 70% (21 of 30) of nonimpaired subjects reported that the presence of an Earth-fixed horizontal line helped them stabilize when their visually enclosed environment was exposed to wave motion. In addition to aiding stability, sensory re-adaptation occurs when inputs from the three sensory systems are synchronized with one another and aligned with Earth’s gravity. The earlier an Earth-fixed visual reference can be introduced the sooner the readaptation process can begin. The goal of this project is to identify the optimal features of a device that visually presents gravitational reference cues to support stability and readaptation. METHODS The capsule sensory-condition simulator is a three-sided enclosure atop a six degree-of-freedom motion platform. A sum-of-sines equation is used to drive the motion platform, producing the simulated wave motion. The equation was derived using the frequency range present in inertial measurement unit (IMU) data collected during open-water Orion mock-up testing. The enclosure creates the nature of a floating visual environment where the walls move in relation to the standing surface. To more accurately represent the condition of postflight crewmembers, galvanic vestibular stimulation (GVS) is applied to disrupt normal vestibular function and standing on a compliant surface attenuates proprioceptive feedback. An instrumented handhold allows the subjects to stabilize themselves and serves as the primary dependent variable. Subjects are instructed to minimize handhold use so the higher forces applied to the handhold correspond to greater instability. Various forms of a visual reference have been explored. Passive systems, such as mechanical gimbals and weighted plumb bobs were eliminated from consideration because of the intertia-induced oscillations that the wave-motion causes. Laser lines presented as horizontal, vertical, or the combination of both are being used to provide the Earth-fixed visual reference. These are presented in the central visual field or periphery from laser sources that are mounted either from within or outside the visual enclosure. RESULTS Data collection for this study is currently in progress. CONCLUSIONS This study will determine whether a visual reference system can help improve stability during challenging sensory conditions and define the optimal chacteristics for such a system.

Brian T Peters↗

NASA NTRSDate not supplied

Developing an Earth-Fixed Visual Reference to Aid Stability, Readaptation, and Egress After A Water Landing

B.T. Peters↗