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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 415 records · Page 23

All sources NASA NTRS DOE OSTI

NASA NTRS1976

Long life coolant pump technology

Design concepts were investigated to improve space system coolant pump technology to be suitable for mission durations of two years and greater. These design concepts included an improved bearing system for the pump rotating elements, consisting of pressurized conical bearings. This design was satisfactorily endurance tested as was a new prototype pump built using various other improved design concepts. Based upon an overall assessment of the results of the program it is concluded that reliable coolant pumps can be designed for three year space missions.

Source record↗

NASA NTRS1981

Electronically commutated dc motors for electric vehicles

A motor development program to explore the feasibility of electronically commutated dc motors (also known as brushless) for electric cars is described. Two different design concepts and a number of design variations based on these concepts are discussed. One design concept is based on a permanent magnet, medium speed, machine rated at 7000 to 9000 rpm, and powered via a transistor inverter power conditioner. The other concept is based on a permanent magnet, high speed, machine rated at 22,000 to 26,000 rpm, and powered via a thyristor inverter power conditioner. Test results are presented for a medium speed motor and a high speed motor each of which have been fabricated using samarium cobalt permanent magnet material.

Maslowski, E. A.↗

NASA NTRS2016

Implementing Effective Mission Systems Engineering Practices During Early Project Formulation Phases

Developing and implementing a plan for a NASA space mission can be a complicated process. The needs, goals, and objectives of any proposed mission or technology must be assessed early in the Project Life Cycle. The key to successful development of a space mission or flight project is the inclusion of systems engineering in early project formulation, namely during Pre-phase A, Phase A, and Phase B of the NASA Project Life Cycle. When a space mission or new technology is in pre-development, or "pre-Formulation", feasibility must be determined based on cost, schedule, and risk. Inclusion of system engineering during project formulation is key because in addition to assessing feasibility, design concepts are developed and alternatives to design concepts are evaluated. Lack of systems engineering involvement early in the project formulation can result in increased risks later in the implementation and operations phases of the project. One proven method for effective systems engineering practice during the pre-Formulation Phase is the use of a mission conceptual design or technology development laboratory, such as the Mission Design Lab (MDL) at NASA's Goddard Space Flight Center (GSFC). This paper will review the engineering process practiced routinely in the MDL for successful mission or project development during the pre-Formulation Phase.

Processes↗

NASA NTRS2019

Evaluation Methodologies for Early Conceptual Design Using Virtual Reality and Physical Test Environments

In this study, human factor design engineers wanted to know, by using subject matter experts (SMEs), if there would be any differences in testing low-fidelity conceptual designs in a physical environment compared to a digital/virtual one. Results indicated that when testing a design concept at this early stage, a high correlation between the two environments exists, meaning SMEs found little to no difference when evaluating a design in either a physical or a digital/virtual environment. There are advantages and limitations to both environments. The virtual world gave the experts a better sense of the microgravity space environment and the relationships of space and human presence that are difficult to simulate in a 1-g physical environment. However, the interaction between human and mechanics is better enhanced in the physical world compared to the virtual world. These advantages and limitations of each environment are important; however, cost is also an important consideration when early design concepts are being used. With the cost analysis of materials, hardware, and labor conducting for this study, virtual reality showed a 68% decrease in cost over the physical mock-up build. Thus, taking all aspects of the study into consideration, at this early design life cycle phase, virtual reality shows great promise as an evaluation environment for testing early design concepts that will cost less, give more options, and increase designer’s time to design.

Harry L. Litaker Jr↗

NASA NTRS2012

Repair Concepts as Design Constraints of a Stiffened Composite PRSEUS Panel

A design and analysis of a repair concept applicable to a stiffened thin-skin composite panel based on the Pultruded Rod Stitched Efficient Unitized Structure is presented. The concept is a bolted repair using metal components, so that it can easily be applied in the operational environment. The damage scenario considered is a midbay-to-midbay saw-cut with a severed stiffener, flange and skin. In a previous study several repair configurations were explored and their feasibility confirmed but refinement was needed. The present study revisits the problem under recently revised design requirements and broadens the suite of loading conditions considered. The repair assembly design is based on the critical tension loading condition and subsequently its robustness is verified for a pressure loading case. High fidelity modeling techniques such as mesh-independent definition of compliant fasteners, elastic-plastic material properties for metal parts and geometrically nonlinear solutions are utilized in the finite element analysis. The best repair design is introduced, its analysis results are presented and factors influencing the design are assessed and discussed.

Przekop, Adam↗

NASA NTRS1983

NTF model concept for the X-29A. Part 2: Design and fabrication concept

The first concept was done to determine if a small model to fit the NASA Langley sizing criteria could accommodate aerodynamic and mechanical requirements. For a model wing span of 1.7 ft (and a length of 3 ft), the model is 6.25 percent (1/16 scale). The results were encouraging enough for Grumman to request, in early December 1981, that the design concept be refined at NASA Langley, where up-to-date cryogenic model design information was available. This working session was completed by a Grumman designer by mid-December. In its present form, the concept will be the basis for any continued effort.

Toscano, G.↗

NASA NTRS1980

Structural concepts for large spacecraft

Design concepts for deployable spacecraft structures are examined with particular emphasis on mass/area optimization, stowability, and assembly, and the relations of these requirements to functional design parameters. Component and modular concepts for platforms and reflectors, structural configurations for long columns, pretension columns, and joint concepts are discussed. A brief overview of astronaut and automated assembly studies is included.

Bush, H. G.↗

NASA NTRS1993

NASA Lewis Meshed VSAT Workshop meeting summary

NASA Lewis Research Center's Space Electronics Division (SED) hosted a workshop to address specific topics related to future meshed very small-aperture terminal (VSAT) satellite communications networks. The ideas generated by this workshop will help to identify potential markets and focus technology development within the commercial satellite communications industry and NASA. The workshop resulted in recommendations concerning these principal points of interest: the window of opportunity for a meshed VSAT system; system availability; ground terminal antenna sizes; recommended multifrequency for time division multiple access (TDMA) uplink; a packet switch design concept for narrowband; and fault tolerance design concepts. This report presents a summary of group presentations and discussion associated with the technological, economic, and operational issues of meshed VSAT architectures that utilize processing satellites.

Ivancic, William↗

NASA NTRS1999

Advance Approach to Concept and Design Studies for Space Missions

Recent automated and advanced techniques developed at JPL have created a streamlined and fast-track approach to initial mission conceptualization and system architecture design, answering the need for rapid turnaround of trade studies for potential proposers, as well as mission and instrument study groups.

Team X Team A Missions Design Proposal Development↗

DOE OSTI2021

Candidate Core Designs for the Transformational Challenge Reactor

Early cycle activities under the Transformational Challenge Reactor (TCR) program focused on analyzing and maturing four reactor core design concepts: two fast-spectrum systems and two thermal-spectrum systems. A rapid, iterative approach has been implemented through which designs can be modified and analyzed and subcomponents can be manufactured in parallel over time frames of weeks rather than months or years. To meet key program initiatives (e.g., timeline, material use), several constraints—including fissile material availability (less than 250 kg of HALEU), component availabilities, materials compatibility, and additive manufacturing capabilities—were factored into the design effort, yielding small (less than one cubic meter in volume) cores with near-term viability. The fast-spectrum designs did not meet the fissile material constraint, so the thermal-spectrum systems became the primary design focus. Since significant progress has been made on advanced moderator materials (YH x ) under the TCR program, gas-cooled thermal-spectrum systems using less than 250 kg of HALEU that occupy less than 1 m 3 are now feasible. The designs for two of these systems have been evolved and matured. In both thermal-spectrum design concepts, bidirectional coolant flow is used. Coolant flows down through YH x moderator elements and is reversed in a bottom manifold and core support structure, and then flows up though or around the fuel elements. The main difference between the two thermal-spectrum design concepts is the fuel elements—one uses traditional UO 2 ceramic fuel, and the other uses UN-bearing TRISO fuel particles embedded inside a SiC matrix. Finally, core neutronics and thermal performance for these systems are assessed and summarized herein.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

NASA NTRS1986

System concepts and design examples for optical communication with planetary spacecraft

Systems concepts for optical communication with future deep-space (planetary) spacecraft are described. These include not only the optical transceiver package aboard the distant spacecraft, but the earth-vicinity optical-communications receiving station as well. Both ground-based, and earth-orbiting receivers are considered. Design examples for a number of proposed or potential deep-space missions are then presented. These include an orbital mission to Saturn, a Lander and Rover mission to Mars, and an astronomical mission to a distance of 1000 astronomical units.

Lesh, James R.↗

NASA NTRS1981

Application of Nonlinear Systems Inverses to Automatic Flight Control Design: System Concepts and Flight Evaluations

A practical method for the design of automatic flight control systems for aircraft with complex characteristics and operational requirements, such as the powered lift STOL and V/STOL configurations, is presented. The method is effective for a large class of dynamic systems requiring multi-axis control which have highly coupled nonlinearities, redundant controls, and complex multidimensional operational envelopes. It exploits the concept of inverse dynamic systems, and an algorithm for the construction of inverse is given. A hierarchic structure for the total control logic with inverses is presented. The method is illustrated with an application to the Augmentor Wing Jet STOL Research Aircraft equipped with a digital flight control system. Results of flight evaluation of the control concept on this aircraft are presented.

Meyer, G.↗

NASA NTRS2010

Lunar Surface Systems Wet-Bath Design Evaluation

The goal of the current evaluation was to examine five different wet-bath architectural design concepts. The primary means of testing the concepts required participants to physically act-out a number of functional tasks (e.g., shaving, showering, changing clothes, maintenance) in order to give judgments on the affordance of the volume as based on the design concepts. Each of the concepts was designed in such a way that certain features were exploited - for example, a concept may have a large amount of internal stowage, but minimum amount of usable space to perform tasks. The results showed that the most preferred concept was one in which stowage and usable space were balanced. This concept allowed for a moderate amount of stowage with some suggested redesign, but would not preclude additional personal items such as clothing. This concept also allowed for a greater distance to be achieved between the toilet and the sink with minimum redesign, which was desirable. Therefore, the all-in-one (i.e., toilet, sink, and shower all occupying a single volume) wet-bath concept seemed to be a viable solution in which there is a minimal amount of overall volume available with certain lunar habitat configurations.

Thompson, Shelby↗

NASA NTRS1986

A Meteorological (humidity, temperature, aerosols)) mobile dial system: Concepts and design

Since 1982 a program was conducted to develop a mobile meteorological (humidity, temperature, aerosols) Differential Absorption Lidar (DIAL) devoted to the studies of the nuclear power plant atmospheric surroundings. The measurement objectives are defined according to the user needs and the lidar feasibility. The concepts and design adopted to meet both the requirement and the measurement objectives are described. Each sub-system is addressed sequentially: transmitting system, receiving system, detection system, and post detection.

Cahen, C.↗

NASA NTRS2007

Orion Entry, Descent, and Landing Performance and Mission Design

The Orion Vehicle is the next spacecraft to take humans into space and will include missions to ISS as well as missions to the Moon. As part of that challenge, the vehicle will have to accommodate multiple mission design concepts, since return from Low Earth Orbit and return from the Moon can be quite different. Commonality between the different missions as it relates to vehicle systems, guidance capability, and operations concepts is the goal. Several unique mission design concepts include the specification of multiple land-based landing sites for a vehicle with closed-loop direct and skip entry guidance, followed by a parachute descent and landing attenuation system. This includes the ability of the vehicle to accurately target and land at a designated landing site, including site location aspects, landing site size, and landing opportunities assessments. Analyses associated with these mission design and flight performance challenges and constraints will be discussed as well as potential operational concepts to provide feasibility and/or mission commonality.

Broome, Joel M.↗

NASA NTRS1974

Lightweight thermally efficient composite feedlines, preliminary design and evaluation

Six liquid hydrogen feedline design concepts were developed for the cryogenic space tug. The feedlines include composite and all-metal vacuum jacketed and non-vacuum jacketed concepts, and incorporate the latest technology developments in the areas of thermally efficient vacuum jacket end closures and standoffs, radiation shields in the vacuum annulus, thermal coatings, and lightweight dissimilar metal flanged joints. The feedline design concepts were evaluated on the basis of thermal performance, weight, cost, reliability, and reusability. It is shown that composite tubing provides improved thermal performance and reduced weight for each design concept considered. Approximately 12 kg (26 lb.) can be saved by the use of composite tubing for the LH2 feedline and the other propulsion lines in the space tug.

Spond, D. E.↗

NASA NTRS1980

Design study of toroidal traction CVT for electric vehicles

The development, evaluation, and optimization of a preliminary design concept for a continuously variable transmission (CVT) to couple the high-speed output shaft of an energy storage flywheel to the drive train of an electric vehicle is discussed. An existing computer simulation program was modified and used to compare the performance of five CVT design configurations. Based on this analysis, a dual-cavity full-toroidal drive with regenerative gearing is selected for the CVT design configuration. Three areas are identified that will require some technological development: the ratio control system, the traction fluid properities, and evaluation of the traction contact performance. Finally, the suitability of the selected CVT design concept for alternate electric and hybrid vehicle applications and alternate vehicle sizes and maximum output torques is determined. In all cases the toroidal traction drive design concept is applicable to the vehicle system. The regenerative gearing could be eliminated in the electric powered vehicle because of the reduced ratio range requirements. In other cases the CVT with regenerative gearing would meet the design requirements after appropriate adjustments in size and reduction gearing ratio.

Raynard, A. E.↗

NASA NTRS1991

Requirements for psychological models to support design: Towards ecological task analysis

Cognitive engineering is largely concerned with creating environmental designs to support skillful and effective human activity. A set of necessary conditions are proposed for psychological models capable of supporting this enterprise. An analysis of the psychological nature of the design product is used to identify a set of constraints that models must meet if they can usefully guide design. It is concluded that cognitive engineering requires models with resources for describing the integrated human-environment system, and that these models must be capable of describing the activities underlying fluent and effective interaction. These features are required in order to be able to predict the cognitive activity that will be required given various design concepts, and to design systems that promote the acquisition of fluent, skilled behavior. These necessary conditions suggest that an ecological approach can provide valuable resources for psychological modeling to support design. Relying heavily on concepts from Brunswik's and Gibson's ecological theories, ecological task analysis is proposed as a framework in which to predict the types of cognitive activity required to achieve productive behavior, and to suggest how interfaces can be manipulated to alleviate certain types of cognitive demands. The framework is described in terms, and illustrated with an example from the previous research on modeling skilled human-environment interaction.

Kirlik, Alex↗