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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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NASA NTRS2004

An Educational Multimedia Presentation on the Introduction to Spacecraft Charging

Over the last few decades, significant knowledge has been gained in how to protect spacecraft from charging; however, the continuing technical advancement in the design and build of satellites requires on-going effort in the study of spacecraft charging. A situation that we have encountered is that not all satellite designers and builders are familiar with the problem of spacecraft charging. The design of a satellite involves many talented people with diverse backgrounds, ranging from manufacturing and assembly to engineering and program management. The complex design and build of a satellite system requires people with highly specialized skills such that cross-specialization is often not achievable. As a result, designers and builders of satellites are not usually familiar with the problems outside their specialization. This is also true for spacecraft charging. Not everyone is familiar with the definition of spacecraft charging and the damage that spacecraft charging can cause. Understanding the problem is an important first step in getting everyone involved in addressing the appropriate spacecraft charging issues during the satellite design and build phases. To address this important first step, an educational multimedia presentation has been created to inform the general engineering community about the basics of spacecraft charging. The content of this educational presentation is based on relevant published technical papers. The presentation was developed using Macromedia Flash. This software produces a more dynamic learning environment than a typical slide show , resulting in a more effective learning experience. The end result is that the viewer will have learned about the basics of spacecraft charging. This presentation is available to the public through our website, www.dplscience.com, free of charge. Viewers are encouraged to pass this presentation to colleagues within their own work environment. This paper describes the content of the multimedia presentation.

Lin, E.↗
NASA NTRS1989

Onboard shuttle on-line software requirements system: Prototype

The prototype discussed here was developed as proof of a concept for a system which could support high volumes of requirements documents with integrated text and graphics; the solution proposed here could be extended to other projects whose goal is to place paper documents in an electronic system for viewing and printing purposes. The technical problems (such as conversion of documentation between word processors, management of a variety of graphics file formats, and difficulties involved in scanning integrated text and graphics) would be very similar for other systems of this type. Indeed, technological advances in areas such as scanning hardware and software and display terminals insure that some of the problems encountered here will be solved in the near-term (less than five years). Examples of these solvable problems include automated input of integrated text and graphics, errors in the recognition process, and the loss of image information which results from the digitization process. The solution developed for the Online Software Requirements System is modular and allows hardware and software components to be upgraded or replaced as industry solutions mature. The extensive commercial software content allows the NASA customer to apply resources to solving the problem and maintaining documents.

Kolkhorst, Barbara↗
NASA NTRS1989

Information system life-cycle and documentation standards, volume 1

The Software Management and Assurance Program (SMAP) Information System Life-Cycle and Documentation Standards Document describes the Version 4 standard information system life-cycle in terms of processes, products, and reviews. The description of the products includes detailed documentation standards. The standards in this document set can be applied to the life-cycle, i.e., to each phase in the system's development, and to the documentation of all NASA information systems. This provides consistency across the agency as well as visibility into the completeness of the information recorded. An information system is software-intensive, but consists of any combination of software, hardware, and operational procedures required to process, store, or transmit data. This document defines a standard life-cycle model and content for associated documentation.

Callender, E. David↗
NASA NTRS2004

Thermomechanical Performance of C and SiC Multilayer, Fiber-Reinforced, CVI SiC Matrix Composites

Hybrid fiber approaches have been attempted in the past to alloy desirable properties of different fiber-types for mechanical properties, thermal stress management, and oxidation resistance. Such an approach has potential for the CrSiC and SiCrSiC composite systems. SiC matrix composites with different stacking sequences of woven C fiber (T300) layers and woven Sic fiber (Hi-NicalonTM) layers were fabricated using the standard CVI process. Delamination occurred to some extent due to thermal mismatch for all of the composites. However, for the composites with a more uniform stacking sequence, minimal delamination occurred, enabling tensile properties to be determined at room temperature and elevated temperatures (stress-rupture in air). Composites were seal-coated with a CVI SiC layer as well as a proprietary C-B-Si (CBS) layer. Definite improvement in rupture behavior was observed in air for composites with increasing SiC fiber content and a CBS layer. The results will be compared to standard C fiber reinforced CVI SiC matrix and Hi-Nicalon reinforced CVI SiC matrix composites.

Morscher, Gregory N.↗
NASA NTRS1985

Orbital transfer vehicle concept definition and system analysis study, 1985. Volume 5: Work breakdown structure and dictionary

To establish consistency and visibility within the Orbital Transfer Vehicle (OTV) program, a preliminary work breakdown structure (WBS) and dictionary were developed. The dictionary contains definitions of terms to be used in conjunction with the WBS so that a clear understanding of the content of the hardware, function, and cost elements may be established. The OTV WBS matrix is a two-dimensional structure which shows the interrelationship of these dimensions: the hardware elements dimension and the phase and function dimension. The dimension of time cannot be shown graphically, but must be considered. Each cost entry varies with time so that it is necessary to know these cost values by year for budget planning and approval as well as for establishing cost streams for discounting purposes in the economic analysis. While a multiple dimensional approach may at first appear complex, it actually provides benefits which outweigh any concern. This structural interrelationship provides the capability to view and analyze the OTV costs from a number of different financial and management aspects. Cost may be summed by hardware groupings, phases, or functions. The WBS may be used in a number of dimensional or single listing format applications.

Nelson, James H.↗
NASA NTRS1994

A rose by any other name: Certification seen as process rather than content

Green (1990) believes that the two main factors safeguarding flying from human error are both related to certification and regulation. First is the increasingly proceduralized nature of flying whereby as much as possible is reduced to a rule-based activity. Second is the emphasis placed upon training and competency checking of aircrew in simulators and in the air, both generally and for all particular types of aircraft flown. This leaves, believes Green, other human factors that are relatively unaddressed as yet and which can give rise to human reliability problems. These include: hardware factors and especially pilot/co-pilot relationships; and system factors including fatigue and cost/safety trade-offs. He also, importantly, identifies problems with the integration of the 'electronic crew member' following increased automation. Human reliability failures with artificial intelligence and automation, due to over-reliance on the system fail-safe mechanisms, or to operator under- confidence in the integrity or self-regulating capacity of the system, or to out-of-loop effects, are widely accepted as being due to deficiencies in plant design, planning, management and maintenance more than to 'operator error' - Reason's (1990) latent error or organization pathogens argument. Reliability failures in complex systems are well enough documented to give cause for concern and at least promote a debate on the merits of a full certification program. The purpose of this short paper is to seek out and explore what is valuable in certification, at the least to show that the benefits outweigh the disadvantages and at best to identify positive outcomes perhaps not obtainable in other ways. On both sides of the debate on certification there is general agreement on the need for a better human factors perspective and effort in complex aviation systems design. What is at issue is how this is to be promoted. It is incumbent upon opponents of certification to say how else such promotion be enabled. This is an exploratory and philosophical review, not a focused and specific one, and it will draw upon much that is not firmly in the domain of complex aviation systems.

Wilson, John R.↗
NASA NTRS2006

Leadership Challenges in ISS Operations: Lessons Learned from Junior and Senior Mission Control Personnel

The International Space Station (ISS) is operated by a multi-national, multi-organizational team that is dispersed across multiple locations, time zones, and work schedules. At NASA, both junior and senior mission control personnel have had to find ways to address the leadership challenges inherent in such work, but neither have had systematic training in how to do so. The goals of this study were to examine the major leadership challenges faced by ISS mission control personnel and to highlight the approaches that they have found most effective to surmount them. We pay particular attention to the approaches successfully employed by the senior personnel and to the training needs identified by the junior personnel. We also evaluate the extent to which responses are consistent across the junior and senior samples. Further, we compare the issues identified by our interview survey to those identified by a standardized questionnaire survey of mission control personnel and a contrasting group of space station crewmembers. We studied a sample of 14 senior ISS flight controllers and a contrasting sample of 12 more junior ISS controllers. Data were collected using a semi-structured qualitative interview and content analyzed using an iterative process with multiple coders and consensus meetings to resolve discrepancies. To further explore the meaning of the interview findings, we also conducted new analyses of data from a previous questionnaire study of 13 American astronauts, 17 Russian cosmonauts, and 150 U.S. and 36 Russian mission control personnel supporting the ISS or Mir space stations. The interview data showed that the survey respondents had substantial consensus on several leadership challenges and on key strategies for dealing with them, and they offered a wide range of specific tactics for implementing these strategies. Interview data from the junior respondents will be presented for the first time at the meeting. The questionnaire data showed that the US mission control sample reported a level of support from their management that compared favorably to national norms. American mission control personnel and Russian crewmembers reported higher supervisor support than American crewmembers and Russian mission control personnel. We will present the specific issues underlying these findings and compare and contrast the results from the two datasets. Although specific to space station personnel, our results are consistent with recent management, cultural, and aerospace research. We aim to use our results to improve training for current and future mission control personnel.

Clement, James L.↗
NASA NTRS2007

Double-Vacuum-Bag Process for Making Resin-Matrix Composites

A double-vacuum-bag process has been devised as a superior alternative to a single-vacuum-bag process used heretofore in making laminated fiber-reinforced resin-matrix composite-material structural components. This process is applicable to broad classes of high-performance matrix resins including polyimides and phenolics that emit volatile compounds (solvents and volatile by-products of resin-curing chemical reactions) during processing. The superiority of the double-vacuum-bag process lies in enhanced management of the volatile compounds. Proper management of volatiles is necessary for making composite-material components of high quality: if not removed and otherwise properly managed, volatiles can accumulate in interior pockets as resins cure, thereby forming undesired voids in the finished products. The curing cycle for manufacturing a composite laminate containing a reactive resin matrix usually consists of a two-step ramp-and-hold temperature profile and an associated single-step pressure profile as shown in Figure 1. The lower-temperature ramp-and-hold step is known in the art as the B stage. During the B stage, prepregs are heated and volatiles are generated. Because pressure is not applied at this stage, volatiles are free to escape. Pressure is applied during the higher-temperature ramp-and-hold step to consolidate the laminate and impart desired physical properties to the resin matrix. The residual volatile content and fluidity of the resin at the beginning of application of consolidation pressure are determined by the temperature and time parameters of the B stage. Once the consolidation pressure is applied, residual volatiles are locked in. In order to produce a void-free, high-quality laminate, it is necessary to design the curing cycle to obtain the required residual fluidity and the required temperature at the time of application of the consolidation pressure.

Bradford, Larry J.↗
NASA NTRSDate not supplied

EMT Project History and Overview

This is a slide set that is part of the 2021 ETM Workshop's planned technical presentations. The content of the presentation is intended to first provide an introduction to the impetus and background that led to ETM and the identified challenges that needed to be considered. Following the introduction, a presentation of early engagement with Industry and other government agencies is provided. The presentation concludes with the early work that followed engagement and the eventual project that ETM was integrated with as well as the eventual formulation of a joint NASA-FAA Research Transition Team.

Upper E Traffic Management↗
NASA NTRS1990

A small missions program for investigation of near-earth asteroids

Current studies are examining the feasibility and possible content of the Discovery Program, a series of 'Explorer-class' missions to planetary targets. Organized as a multi-layer program with constant funding, the Discovery Program would support lower cost exploration opportunities that are missed in the new start procedure for larger missions. One approach to such a program is to focus on rendezvous missions to several near-Earth asteroids to characterize basic properties of this group of objects. A sample program is presented that visits six different targets over twelve years, using direct low energy trajectories; some of these are newly identified. Each flight in the program delivers a payload capable of addressing science objectives within the expected budget and programmatic constraints of small planetary missions. The key to satisfying the constraints is a disciplined program management philosophy, consistently applied over the entire program, that makes extensive use of hardware designs developed for other programs.

Stancati, M. L.↗
NASA NTRS2017

Creative Analytics of Mission Ops Event Messages

Historically, tremendous effort has been put into processing and displaying mission health and safety telemetry data; and relatively little attention has been paid to extracting information from missions time-tagged event log messages. Todays missions may log tens of thousands of messages per day and the numbers are expected to dramatically increase as satellite fleets and constellations are launched, as security monitoring continues to evolve, and as the overall complexity of ground system operations increases. The logs may contain information about orbital events, scheduled and actual observations, device status and anomalies, when operators were logged on, when commands were resent, when there were data drop outs or system failures, and much much more. When dealing with distributed space missions or operational fleets, it becomes even more important to systematically analyze this data. Several advanced information systems technologies make it appropriate to now develop analytic capabilities which can increase mission situational awareness, reduce mission risk, enable better event-driven automation and cross-mission collaborations, and lead to improved operations strategies: Industry Standard for Log Messages. The Object Management Group (OMG) Space Domain Task Force (SDTF) standards organization is in the process of creating a formal standard for industry for event log messages. The format is based on work at NASA GSFC. Open System Architectures. The DoD, NASA, and others are moving towards common open system architectures for mission ground data systems based on work at NASA GSFC with the full support of the commercial product industry and major integration contractors. Text Analytics. A specific area of data analytics which applies statistical, linguistic, and structural techniques to extract and classify information from textual sources. This presentation describes work now underway at NASA to increase situational awareness through the collection of non-telemetry mission operations information into a common log format and then providing display and analytics tools to provide in-depth assessment of the log contents. The work includes: Common interface formats for acquiring time-tagged text messages Conversion of common files for schedules, orbital events, and stored commands to the common log format Innovative displays to depict thousands of messages on a single display Structured English text queries against the log message data store, extensible to a more mature natural language query capability Goal of speech-to-text and text-to-speech additions to create a personal mission operations assistant to aid on-console operations. A wide variety of planned uses identified by the mission operations teams will be discussed.

events↗
NASA NTRS2003

A Comprehension Based Analysis of Autoflight System Interfaces

This cooperative agreement supported Dr. Peter Polson's participation in two interrelated research programs. The first was the development of the Situation-Goal-Behavior (SGB) Model that is both a formal description of an avionics system's logic and behavior and a representation of a system that can be understood by avionics designers, pilots, and training developers. The second was the development of a usability inspection method based on an approximate model, RAFIV, of pilot interactions with the Flight Management System (FMS). The main purpose of this report is to integrate the two models and provide a context in order to better characterize the accomplishments of this research program. A major focus of both the previous and this Cooperative Agreement was the development of usability evaluation methods that can be effectively utilized during all phases of the design, development, and certification process of modern avionics systems. The current efforts to validate these methods have involved showing that they generate useful analyses of known operational and training problems with the current generation of avionics systems in modern commercial airliners. This report is organized into seven sections. Following the overview, the second section describes the Goal-Situation-Behavior model and its applications. The next section summarizes the foundations of the RAFIV model and describes the model in some detail. The contents of both these sections are derived from previous reports referenced in footnotes. The fourth section integrates these two models into a complete design evaluation and training development framework. The fifth section contains conclusions and possible future directions for research. References are in Section 6. Section 7 contains the titles and abstracts of the papers paper describing in more detail the results of this research program.

Palmer, Everett↗
NASA NTRS2006

Leadership and Cultural Challenges in Operating the International Space Station

Operating the International Space Station (ISS) involves an indefinite, continuous series of long-duration international missions, and this requires an unprecedented degree of cooperation across multiple sites, organizations, and nations. ISS flight controllers have had to find ways to maintain effective team performance in this challenging new context. The goal of this study was to systematically identify and evaluate the major leadership and cultural challenges faces by ISS flight controllers, and to highlight the approaches that they have found most effective to surmount these challenges. We conducted a qualitative survey using a semi-structured interview. Subjects included 14 senior NASA flight controllers who were chosen on the basis of having had substantial experience working with international partners. Data were content analyzed using an iterative process with multiple coders and consensus meetings to resolve discrepancies. To further explore the meaning of the interview findings, we also conducted some new analyses of data from a previous questionnaire study of Russian and American ISS mission control personnel. The interview data showed that respondents had substantial consensus on several leadership and cultural challenges and on key strategies for dealing with them, and they offered a wide range of specific tactics for implementing these strategies. Surprisingly few respondents offered strategies for addressing the challenge of working with team members whose native language is not American English. The questionnaire data showed that Americans think it is more important than Russians that mission control personnel speak the same dialect of one shared common language. Although specific to the ISS program, our results are consistent with recent management, cultural, and aerospace research. We aim to use our results to improve training for current and future ISS flight controllers.

Clement, J. L.↗
NASA NTRS2008

Web Based Tool for Mission Operations Scenarios

A conventional practice for spaceflight projects is to document scenarios in a monolithic Operations Concept document. Such documents can be hundreds of pages long and may require laborious updates. Software development practice utilizes scenarios in the form of smaller, individual use cases, which are often structured and managed using UML. We have developed a process and a web-based scenario tool that utilizes a similar philosophy of smaller, more compact scenarios (but avoids the formality of UML). The need for a scenario process and tool became apparent during the authors' work on a large astrophysics mission. It was noted that every phase of the Mission (e.g., formulation, design, verification and validation, and operations) looked back to scenarios to assess completeness of requirements and design. It was also noted that terminology needed to be clarified and structured to assure communication across all levels of the project. Attempts to manage, communicate, and evolve scenarios at all levels of a project using conventional tools (e.g., Excel) and methods (Scenario Working Group meetings) were not effective given limitations on budget and staffing. The objective of this paper is to document the scenario process and tool created to offer projects a low-cost capability to create, communicate, manage, and evolve scenarios throughout project development. The process and tool have the further benefit of allowing the association of requirements with particular scenarios, establishing and viewing relationships between higher- and lower-level scenarios, and the ability to place all scenarios in a shared context. The resulting structured set of scenarios is widely visible (using a web browser), easily updated, and can be searched according to various criteria including the level (e.g., Project, System, and Team) and Mission Phase. Scenarios are maintained in a web-accessible environment that provides a structured set of scenario fields and allows for maximum visibility across the project. One key aspect is that the tool was built for a scenario process that accounts for stakeholder input, review, comment, and concurrence. By creating well-designed opportunities for stakeholder input and concurrence and by making the scenario content easily accessible to all project personnel, we maximize the opportunities for stakeholders to both understand and agree on the concepts for how their mission is to be carried out.

Boyles, Carole A.↗
NASA NTRSDate not supplied

Investigating Risks Due to Artemis EVA Tempo Via Probabilistic Risk Assessment

Spaceflight operations pose unique challenges to crew health, safety, and resource management. As space agencies and private companies continue to push the boundaries of human exploration, it is essential to understand the risks associated with Extravehicular Activities (EVAs) and develop strategies to mitigate them. The tempo at which EVAs are conducted – the total number and frequency of these activities – can have a profound impact on medical risks, resource consumption, and overall mission success. Probabilistic risk assessment (PRA) provides a powerful framework for evaluating complex systems and identifying potential hazards. Our work employs the Medical Extensible Dynamic Probabilistic Risk Assessment Tool (MEDPRAT) [1] to simulate mission events, occurrence and treatment of medical conditions, and track the utilization of resources. Coupled with the Evidence Library [2], a medical evidence base for exploration-class missions developed by the Exploration Medical Capability within NASA’s Human Research Program, we can estimate these risks with increased fidelity and optimize medical kit contents to meet specific mission requirements. This presentation provides a detailed examination of how EVA tempo influences medical risk estimates for a lunar surface design reference mission. A comprehensive analysis is conducted to assess the additional mass and volume burden imposed on medical kits required to maintain adequate levels of risk mitigation. Furthermore, we estimate the distribution of the number of successful EVAs completed based on the level of task impairment imposed by medical events and flight rules related to specific medical events, such as decompression sickness.

Modeling↗
NASA NTRS1998

The Conference Proceedings of the 1998 Air Transport Research Group (ATRG) of the WCTR Society

Contents include the following: Airport choice in a multiple airport region: an empirical analysis for the San Francisco bay area. Liberalization of the westeuropian aviation: choice of a new hub airport for an airline. Austin Bergstrom airport traffic control tower establishment of a major activity level tower. A study to optimize the environmental capacity of Amsterdam airport schiphol.Airport performance in stakeholder involvement and communication strategies: a comparison of major Australian and North American air carrier and general aviation airports. Airport planning and location.Location of international airport and regional development. A simulation technique for analysis of Brasilian airport passanger terminal building.Multimodal airport access in Japan. Planning surface access provision at major airports Airline economics and the inclusion of environmental costs on airport hub pricing: a theoretical analysis. Airport financing and user charge systems in the USA. Optimal demand for operating lease of aircraft. Aircraft leasing industry and social welfare.The development of performance indicators for airports: a management perspective. Study about operational effect of the "security check-in" implantation in Brasilian international airports.Austin Bergstrom west loop cable system.and Optimal resource allocation model for airport passanger terminals.

Oum, Tae Hoon↗
NASA NTRS2007

Master Metadata Repository and Metadata-Management System

A master metadata repository (MMR) software system manages the storage and searching of metadata pertaining to data from national and international satellite sources of the Global Ocean Data Assimilation Experiment (GODAE) High Resolution Sea Surface Temperature Pilot Project [GHRSSTPP]. These sources produce a total of hundreds of data files daily, each file classified as one of more than ten data products representing global sea-surface temperatures. The MMR is a relational database wherein the metadata are divided into granulelevel records [denoted file records (FRs)] for individual satellite files and collection-level records [denoted data set descriptions (DSDs)] that describe metadata common to all the files from a specific data product. FRs and DSDs adhere to the NASA Directory Interchange Format (DIF). The FRs and DSDs are contained in separate subdatabases linked by a common field. The MMR is configured in MySQL database software with custom Practical Extraction and Reporting Language (PERL) programs to validate and ingest the metadata records. The database contents are converted into the Federal Geographic Data Committee (FGDC) standard format by use of the Extensible Markup Language (XML). A Web interface enables users to search for availability of data from all sources.

Armstrong, Edward↗
NASA NTRS2014

Can Cell to Cell Thermal Runaway Propagation be Prevented in a Li-ion Battery Module?

Increasing cell spacing decreased adjacent cell damage center dotElectrically connected adjacent cells drained more than physically adjacent cells center dotRadiant barrier prevents propagation when fully installed between BP cells center dotBP cells vent rapidly and expel contents at 100% SOC -Slower vent with flame/smoke at 50% -Thermal runaway event typically occurs at 160 degC center dotLG cells vent but do not expel contents -Thermal runaway event typically occurs at 200 degC center dotSKC LFP modules did not propagate; fuses on negative terminal of cell may provide a benefit in reducing cell to cell damage propagation. New requirement in NASA-Battery Safety Requirements document: JSC 20793 Rev C 5.1.5.1 Requirements - Thermal Runaway Propagation a. For battery designs greater than a 80-Wh energy employing high specific energy cells (greater than 80 watt-hours/kg, for example, lithium-ion chemistries) with catastrophic failure modes, the battery shall be evaluated to ascertain the severity of a worst-case single-cell thermal runaway event and the propensity of the design to demonstrate cell-to-cell propagation in the intended application and environment. NASA has traditionally addressed the threat of thermal runaway incidents in its battery deployments through comprehensive prevention protocols. This prevention-centered approach has included extensive screening for manufacturing defects, as well as robust battery management controls that prevent abuse-induced runaway even in the face of multiple system failures. This focused strategy has made the likelihood of occurrence of such an event highly improbable. b. The evaluation shall include all necessary analysis and test to quantify the severity (consequence) of the event in the intended application and environment as well as to identify design modifications to the battery or the system that could appreciably reduce that severity. In addition to prevention protocols, programs developing battery designs with catastrophic failure modes should take the steps necessary to assess the severity of a possible thermal runaway event. Programs should assess whether there are reasonable design changes that could appreciably affect the severity of the outcome. Evaluation should include environmental effects to surrounding hardware (i.e., temperature, pressure, shock), contamination effects due to any expelled contaminates, and venting propulsive effects when venting overboard.

Jeevarajan, Judith↗