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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 1,027 records · Page 57
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Development of a funding, cost, and spending model for satellite projects

The need for a predictive budget/funging model is obvious. The current models used by the Resource Analysis Office (RAO) are used to predict the total costs of satellite projects. An effort to extend the modeling capabilities from total budget analysis to total budget and budget outlays over time analysis was conducted. A statistical based and data driven methodology was used to derive and develop the model. Th budget data for the last 18 GSFC-sponsored satellite projects were analyzed and used to build a funding model which would describe the historical spending patterns. This raw data consisted of dollars spent in that specific year and their 1989 dollar equivalent. This data was converted to the standard format used by the RAO group and placed in a database. A simple statistical analysis was performed to calculate the gross statistics associated with project length and project cost ant the conditional statistics on project length and project cost. The modeling approach used is derived form the theory of embedded statistics which states that properly analyzed data will produce the underlying generating function. The process of funding large scale projects over extended periods of time is described by Life Cycle Cost Models (LCCM). The data was analyzed to find a model in the generic form of a LCCM. The model developed is based on a Weibull function whose parameters are found by both nonlinear optimization and nonlinear regression. In order to use this model it is necessary to transform the problem from a dollar/time space to a percentage of total budget/time space. This transformation is equivalent to moving to a probability space. By using the basic rules of probability, the validity of both the optimization and the regression steps are insured. This statistically significant model is then integrated and inverted. The resulting output represents a project schedule which relates the amount of money spent to the percentage of project completion.

Johnson, Jesse P.↗
NASA NTRS1976

Study of short-haul aircraft operating economics. Phase 2: An analysis of the impact of jet modernization on local service airline operating costs

The objectives of this phase of the study were (1) to assess the 10 year operating cost trends of the local service airlines operating in the 1965 through 1974 period, (2) to glean from these trends the technological and operational parameters which were impacted most significantly by the transition to newer pure jet, short haul transports, and effected by changing fuel prices and cost of living indices, and (3) to develop, construct, and evaluate an operating cost forecasting model which would incorporate those factors which best predicted airline total operating cost behavior over that 10-year period.

Andrastek, D. A.↗
NASA NTRS2020

Development of a Compact, Low Cost Test Fixture to Evaluate Creep in High Strength Softgoods Materials under Constant Environmental Control

Space exploration is typically driven by two key factors: cost and payload mass. Therefore creating relatively low cost, low mass space hardware is critical. With the advancement of new high-strength flexible materials, a new chapter is opening in the evolution of pressurized space structures. Space-rated inflatable structures are attractive due to their low mass, compact stowage, and capability of performing as well, or better than, their rigid counterparts for applications such as habitats and airlocks. The lifetime properties of materials used for inflatable structures are not as well characterized as heritage composite and metallic materials; therefore, they require extensive testing to increase the level of confidence in their use. Creep testing is one method of evaluating the expected lifetime of materials that may be under constant load for many years in operational use. Conventional creep testing of high-strength softgoods webbings or cordage requires a large, temperature-controlled facility, with structural frames capable of supporting large dead weights, weighing thousands of pounds on each specimen. This is expensive and takes up a significant amount of volume in a facility for a long time. This paper describes the design and analysis of a low-cost, low-volume creep test stand that can be locally environmentally controlled, so that smaller, cheaper facilities can be used for characterizing the creep life of the softgoods materials used in inflatable space structures.

Softgoods↗
NASA NTRS2023

EVA Task and 3D Pose Recognition from Video

Extravehicular Activity (EVA) has been known to involve potential risks of biomechanical stresses and injuries to crewmembers. Gathering of EVA motion patterns is necessary for risk analysis and mitigation. However, many existing techniques, such as motion capture systems, are not only cost-prohibitive but are impractical for retrospective analysis of past missions. In this work, a software tool was developed, which can estimate the 3D poses of a spacesuit from photographs or videos, without using special sensors or equipment. The tool is based on the state-of-the-art artificial intelligence and machine learning (AI/ML) system, which was trained by studying and capturing motion patterns of past and current spacesuit test data. The AI/ML tool was further enhanced using synthetically generated data, in which the suit postures, backgrounds, camera angles and illumination conditions were parametrically adjusted and rendered for training. The tool, incorporated the methodologies of Convolutional Neural Network (CNN), was trained, and tested in the cloud computing environment. The trained model was then applied on new imagery and video to extract estimated joint positions and suit outlines. The joint positions were further processed to capture activity (“digging”), pose labels (“bending”), and other useful downstream information. The model performance on new imagery and video was successfully assessed for accuracy and reliability. This AI/ML based posture recognition tool thus allows for the quantification of injury risk and task performance characterization for both current and past missions and training, which can immensely help to improve EVA task and suit design.

Kyung Han Kim↗
NASA NTRS1986

Study of selected tether applications in space, phase 3, volume 2

The results of a Phase 3 study of two Selected Tether Applications in Space (STAIS); deorbit of a Shuttle and launch of an Orbital Transfer Vehicle (OTV), both from the space station using a tether were examined. The study objectives were to: perform a preliminary engineering design, define operational scenarios, develop a common cost model, perform cost benefits analyses, and develop a Work Breakdown Structure (WBS). Key features of the performance analysis were to identify the net increases in effective Shuttle cargo capability if tethers are used to assist in the deorbit of Shuttles and the launching of the OTVs from the space station and to define deployer system designs required to accomplish these tasks. Deployer concepts were designed and discussed. Operational scenarios, including timelines, for both tethered and nontethered Shuttle and OTV operations at the space station were evaluated. A summary discussion of the Selected Tether Applications Cost Model (STACOM) and the results of the cost benefits analysis are presented. Several critical technologies needed to implement tether assisted deployment of payloads are also discussed. Conclusions and recommendations are presented.

Source record↗
NASA NTRS1968

Automatic planning concept - An analysis of optimum scheduling

Study considers resource costs, mission constraints, and experiment results as linear functions, insofar as possible, in an effort to develop optimum scheduling by the use of linear programming. It involves a mathematical approach in which a number of constraints are considered operative.

Rebelein, P. R.↗
NASA NTRS1978

Reduction of liquid hydrogen boiloff: Optimal reliquefaction system design and cost study

A preliminary design and economic analysis of candidate hydrogen reliquefaction systems was performed. All candidate systems are of the same general type; differences and size, compressor arrangement, and amount of hydrogen venting. The potential application of the hydrogen reliquefaction will be to reduce the boil-off from the 850,000 gallon storage dewars at LC-39.

Source record↗
NASA NTRS1979

Manned Orbital Transfer Vehicle (MOTV). Volume 5: Turnaround analysis

The development of a low-cost reliable turnaround process to employ the MOTV in enhancing the utilization of the geosynchronous space region is analyzed. It is indicated that a routine effective turnaround/maintenance plan must make maximum use of flight data for maintenance planning, a high degree of test automation, and MOTV maintainability features in order to minimize tests, facilitate repair, and reduce manpower requirements. An effective turnaround plan provides a payback of reduced risks.

Boyland, R. E.↗
NASA NTRS1986

Risk and value analysis of SETI

The risks, values, and costs of the SETI project are evaluated and compared with those of the Viking project. Examination of the scientific values, side benefits, and costs of the two projects reveal that both projects provide equal benefits at equal costs. The probability of scientific and technical success is analyzed.

Billingham, J.↗
NASA NTRS1990

Thermal Analysis

Packaging engineers can avoid unnecessary and costly redesign of product through use of tools such as the SINDA '85/FLUINT software system for predicting thermal performance of electronic aviation equipment. SINDA '85/FLUINT is an acronym for Systems Improved Numerical Differencing Analyzer and Fluid Integrators. It is a program for solving the physical problems governed by flow and diffusion type equations and is most widely used as a general thermal analyzer.

Source record↗
NASA NTRS2002

Goddard's New Data Analysis System

After evaluating the total lifetime costs of various commercial systems, it was determined that an in-house development would be more cost-effective in the long run. Matlab was chosen as the development platform, since it is now being taught to most engineering students. The presentation will discuss the specifications of the system.

Worth, Daniel B.↗
NASA NTRS1990

On-orbit assembly/servicing task definition study

The OEXP vehicles being envisioned to carry out the Presidential space goals of a lunar outpost and human exploration of Mars will require on-orbit assembly, refurbishment, checkout, and launch. The On-orbit Assembly/Servicing Task Definition Study applies the space vehicle processing experience and procedures archives resident at NASA's Kennedy Space Center (KSC) to determine the task flows, and resources/facilities necessary to process the OEXP vehicles at Space Station Freedom (SSF). This data base is examined to find the closest analogies to OEXP vehicle components and assembly/refurbishment tasks. Transition tables are generated to provide traceability from KSC hardware processing experience to analogous on-orbit processing of the OEXP vehicles. Iterations in which the task flows are broken down into realistic extravehicular activity (EVA) primitive subtasks and times, and to apply automation and robotic technology to reduce crew risks and minimize EVA time, will enhance the value and accuracy of the predicted flows. These processing scenarios and the resulting resource/facility requirements are used to determine impacts of SSF, resulting in change requests to SSF requirements for provision of 'hooks and scars' to evolve the assembly complete Space Station into a transportation node. Study results to date include assembly analysis of the Martin Marietta Phobos Gateway Vehicle, refurbishment analysis of the Martin Marietta Lunar Evolution Piloted and Cargo Vehicles, and assembly analysis of the Boeing Mars Evolution Vehicle. The results of this study will be accumulated into the vehicle processing operations data base for subsequent modeling, life cycle cost, vehicle growth, and SSF impact analysis.

Vargo, Rick↗
NASA NTRS2023

Market Analysis of the Subsonic Single Aft Engine (SUSAN) Transport Aircraft Concept

This paper presents a detailed market analysis of the U.S. domestic aviation market in support of the NASA subsonic single aft engine (SUSAN) regional aircraft concept. The current scoping of the SUSAN concept is intended to compete in the medium to large (160-180 seats) narrow body market, with range capabilities of up to 2,500 nautical miles, and expected fuel burn reduction up to 40% relative to conventional 2 engine aircraft. Recent historical trends suggest growth in aviation passenger demand will continue to be met by the narrow body fleet of aircraft; however, a comprehensive review is required to understand how these current fleet trends could evolve in the future. Moreover, estimating and forecasting the potential market size is the critical first step when developing a new aircraft concept to determine commercial viability. To assist in the trade space exploration of the SUSAN concept, a generalized traffic and fleet forecast of the U.S. aviation market is conducted. Using publicly available aviation data from the U.S. Bureau of Transportation Statistics and passenger demand forecasts from FAA, a multinomial logit model is estimated to predict the composition of the future fleet by aircraft size. These fleet forecasts are then used as inputs for a fleet evolution model to provide required operational forecasts at the aircraft specific level. Forecast scenarios with and without the SUSAN concept are compared, and a breakeven analysis is performed to evaluate the commercial viability of the SUSAN aircraft from an operating cost perspective. Results from the multinomial logit fleet forecast indicate the narrow body size category of 150+ seats dominating the market, comprising 87% of the future revenue passenger miles market share in 2050 (up from 60% in 2019). Forecast scenarios with the SUSAN concept see a maximum cumulative decline in fuel cost of 20% by 2050, while a breakeven analysis shows competitive advantage of the SUSAN aircraft, due to expected fuel burn reduction, at moderate levels of increased maintenance and capital costs.

Jacob M. Wishart↗
NASA NTRS2002

Failure Mode Identification Through Clustering Analysis

Research has shown that nearly 80% of the costs and problems are created in product development and that cost and quality are essentially designed into products in the conceptual stage. Currently, failure identification procedures (such as FMEA (Failure Modes and Effects Analysis), FMECA (Failure Modes, Effects and Criticality Analysis) and FTA (Fault Tree Analysis)) and design of experiments are being used for quality control and for the detection of potential failure modes during the detail design stage or post-product launch. Though all of these methods have their own advantages, they do not give information as to what are the predominant failures that a designer should focus on while designing a product. This work uses a functional approach to identify failure modes, which hypothesizes that similarities exist between different failure modes based on the functionality of the product/component. In this paper, a statistical clustering procedure is proposed to retrieve information on the set of predominant failures that a function experiences. The various stages of the methodology are illustrated using a hypothetical design example.

Arunajadai, Srikesh G.↗
NASA NTRS2005

Failure Assessment

Three questions to which software developers want accurate, precise answers are "How can the software system fail?", "mat bad things will happen if the software fails?t', and "How many failures will the software experience?". Numerous techniques have been devised to answer these questions; three of the best known are: 1) Software Fault Tree Analysis (SFTA) 2) Software Failure Modes, Effects, and Criticality Analysis (SFMECA 3) Software Fault/Failure Modeling. SFTA and SFMECA have been successfully used to analyze the flight software for a number of robotic planetary exploration missions, including Galileo, Cassini, and Deep Space 1. Given the increasing interest in reusing software components from mission to mission, one of us has developed techniques for reusing the corresponding portions of the SFTA and SFMECA, reducing the effort required to conduct these analyses. SFTA has also been shown to be effective in analyzing the security aspects of software systems; intrusion mechanisms and effects can easily be modeled using these techniques. The Bi- Directional Safety Analysis (BDSA) method combines a forward search (similar to SFMECA) from potential failure modes to their effects, with a backward search (similar to SFTA) from feasible hazards to the contributing causes of each hazard. BDSA offers an efficient way to identify latent failures. Recent work has extended BDSA to product-line applications such as flight-instrumentation displays and developed tool support for the reuse of the failure-analysis artifacts within a product line. BDSA has also been streamlined to support those projects having tight cost and/or schedule constraints for their failure analysis efforts. We discuss lessons learned from practice, describe available tools, and identi@ some future directions for the topic. A substantial amount of research has been devoted to estimating the number of failures that a software system will experience during test and operations, as well as the number of faults that have been inserted into that system during its development. One of us has found that the amount of structural change to a system during its development is strongly related to the number of faults inserted into it. Using techniques requiring no additional effort on the part of the development organization, the required measurements of structural evolution can be easily obtained from a development effort's configuration management system and readily transformed into an estimate of fault content. So far, structure-fault relationships have been identified for source code; current work seeks to examine artifacts available earlier in the lifecycle to determine if similar relationships between structure and fault content can be found. In particular, relationships between requirements change requests and the number of faults inserted into the implemented system would provide a significant improvement in our ability to control software quality during the early development phases.

fault tree↗