A study of adaptive multimode systems Final technical report, Mar. 1967 - Apr. 1968
Laboratory model of experiment for demonstrating applicability of adaptive multimode systems concept to scientific spacecraft instrumentation
Cummings, J. R.↗
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Four-D global reference atmosphere technical description, part 1
An empirical atmospheric model was developed which generates values for pressure, density, temperature, and winds from surface levels to orbital altitudes. The output parameters consist of components for: (1) latitude, longitude, and altitude dependent monthly and annual means; (2) quasi-biennial oscillations; and (3) random perturbations to simulate partially the variability due to synoptic, diurnal, planetary wave, and gravity wave variations. Quasi-biennial and random variation perturbations are computed from parameters determined from various empirical studies and are added to the monthly mean values. This model has been developed as a computer program called PROFILE which can be used to generate altitude profiles of atmospheric parameters along any simulated trajectory through the atmosphere. The PROFILE program was developed for design applications in the space shuttle program. Other applications of the model are discussed, such as for global circulation and diffusion studies, and for generating profiles for comparison with other atmospheric measurement techniques, (e.g. satellite measured temperature profiles).
Justus, C. G.↗
History of wind shear turbulence models
The Office of Flight Operations, Flight Technical Programs Div., at the FAA Headquarters, interfaces with industry, R&D communities and air carriers during the introduction of new types of equipment into operational services. A brief highlight of the need which FAA operations sees for new wind shear and turbulence data sets from the viewpoint of equipment certification and simulation is presented.
Cusimano, Lou↗
Software Development Cost: How Much? You Sure? Technical Summary
This viewgraph presentation reviews cost models to properly estimate the cost of software development.
machine learning↗
NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 37: The impact of political control on technical communications: A comparative study of Russian and US aerospace engineers and scientists
Until the recent dissolution of the Soviet Union, the Communist Party exerted a strict control of access to and dissemination of scientific and technical information (STI). This article presents models of the Soviet-style information society and the Western-style information society and discusses the effects of centralized governmental control of information on Russian technical communication practices. The effects of political control on technical communication are then used to interpret the results of a survey of Russian and U.S. aerospace engineers and scientists concerning the time devoted to technical communication, their collaborative writing practices and their attitudes toward collaboration, the kinds of technical documents they produce and use, and their use of computer technology, and their use of and the importance to them of libraries and technical information centers. The data are discussed in terms of tentative conclusions drawn from the literature. Finally, we conclude with four questions concerning government policy, collaboration, and the flow of STI between Russian and U.S. aerospace engineers and scientists.
Barclay, Rebecca O.↗
NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 32: A new era in international technical communication: American-Russian collaboration
Until the recent dissolution of the Soviet Union, the Communist Party exerted a strict control of access to and dissemination of scientific and technical information (STI). This article presents models of the Soviet-style information society and the Western-style information society and discusses the effects of centralized governmental control of information on Russian technical communication practices. The effects of political control on technical communication are then used to interpret the results of a survey of Russian and U.S. aerospace engineers and scientists concerning the time devoted to technical communication, their collaborative writing practices and their attitudes toward collaboration, the kinds of technical documents they produce and use, their views regarding the appropriate content for an undergraduate technical communication course, and their use of computer technology. Finally, the implications of these findings for future collaboration between Russian and U.S. engineers and scientists are examined.
Flammia, Madelyn↗
Crop area estimation based on remotely-sensed data with an accurate but costly subsample
Research activities conducted under the auspices of National Aeronautics and Space Administration Cooperative Agreement NCC 9-9 are discussed. During this contract period research efforts are concentrated in two primary areas. The first are is an investigation of the use of measurement error models as alternatives to least squares regression estimators of crop production or timber biomass. The secondary primary area of investigation is on the estimation of the mixing proportion of two-component mixture models. This report lists publications, technical reports, submitted manuscripts, and oral presentation generated by these research efforts. Possible areas of future research are mentioned.
Gunst, R. F.↗
Development and application of dynamic simulations of a subsonic wind tunnel
Efforts are currently underway at NASA Lewis to improve and expand ground test facilities and to develop supporting technologies to meet anticipated aeropropulsion research needs. Many of these efforts have been focused on a proposed rehabilitation of the Altitude Wind Tunnel (AWT). In order to insure a technically sound design, an AWT modeling program (both analytical and physical) was initiated to provide input to the AWT final design process. This paper describes the approach taken to develop analytical, dynamic computer simulations of the AWT, and the use of these simulations as test-beds for: (1) predicting the dynamic response characteristics of the AWT, and (2) evaluating proposed AWT control concepts. Plans for developing a portable, real-time simulator for the AWT facility are also described.
Szuch, J. R.↗
Development and application of dynamic simulations of a subsonic wind tunnel
Efforts are currently underway at NASA Lewis to improve and expand ground test facilities and to develop supporting technologies to meet anticipated aeropropulsion research needs. Many of these efforts have been focused on a proposed rehabilitation of the Altitude Wind Tunnel (AWT). In order to insure a technically sound design, an AWT modeling program (both analytical and physical) was initiated to provide input to the AWT final design process. This paper describes the approach taken to develop analytical, dynamic computer simulations of the AWT, and the use of these simulations as test-beds for (1) predicting the dynamic response characteristics of the AWT and (2) evaluating proposed AWT control concepts. Plans for developing a portable, real-time simulator for the AWT facility are also described.
Szuch, J. R.↗
Evaluation of cryogenic system test options for the OTV on-orbit propellant depot
Future space missions to geosynchronous, lunar, and planetary orbits will require an orbital depot for stockpiling propellants. This depot will provide long-term storage of cryogens, requiring new technologies for fluid management in microgravity and further development of thermal management technologies for minimization of cryogen boiloff. Preliminary evaluations have been made to define a test program approach for reducing technical risk through verifying performance models and building a base of engineering data for depot design. A number of testing options were defined and evaluated, leading to selection of ground testing combined with an orbital systems test. Ground testing is inadequate because of critical microgravity concerns; extending testing aboard the Space Station was eliminated because the data would not be available soon enough to benefit the propellant depot design. The orbital test would either be a short-term test carried out in the cargo bay of the Space Shuttle Orbiter using a nonhazardous cryogen or a longer term test carried out with hydrogen aboard a free-flying experiment orbited with an expendable launch vehicle.
Schuster, John R.↗
ATOS-1: Designing the infrastructure for an advanced spacecraft operations system
The space industry has identified the need to use artificial intelligence and knowledge based system techniques as integrated, central, symbolic processing components of future mission design, support and operations systems. Various practical and commercial constraints require that off-the-shelf applications, and their knowledge bases, are reused where appropriate and that different mission contractors, potentially using different KBS technologies, can provide application and knowledge sub-modules of an overall integrated system. In order to achieve this integration, which we call knowledge sharing and distributed reasoning, there needs to be agreement on knowledge representations, knowledge interchange-formats, knowledge level communications protocols, and ontology. Research indicates that the latter is most important, providing the applications with a common conceptualization of the domain, in our case spacecraft operations, mission design, and planning. Agreement on ontology permits applications that employ different knowledge representations to interwork through mediators which we refer to as knowledge agents. This creates the illusion of a shared model without the constraints, both technical and commercial, that occur in centralized or uniform architectures. This paper explains how these matters are being addressed within the ATOS program at ESOC, using techniques which draw upon ideas and standards emerging from the DARPA Knowledge Sharing Effort. In particular, we explain how the project is developing an electronic Ontology of Spacecraft Operations and how this can be used as an enabling component within space support systems that employ advanced software engineering. We indicate our hope and expectation that the core ontology developed in ATOS, will permit the full development of standards for such systems throughout the space industry.
Poulter, K. J.↗
Comprehensive Design Reliability Activities for Aerospace Propulsion Systems
This technical publication describes the methodology, model, software tool, input data, and analysis result that support aerospace design reliability studies. The focus of these activities is on propulsion systems mechanical design reliability. The goal of these activities is to support design from a reliability perspective. Paralleling performance analyses in schedule and method, this requires the proper use of metrics in a validated reliability model useful for design, sensitivity, and trade studies. Design reliability analysis in this view is one of several critical design functions. A design reliability method is detailed and two example analyses are provided-one qualitative and the other quantitative. The use of aerospace and commercial data sources for quantification is discussed and sources listed. A tool that was developed to support both types of analyses is presented. Finally, special topics discussed include the development of design criteria, issues of reliability quantification, quality control, and reliability verification.
Christenson, R. L.↗
Heuristics Applied in the Development of Advanced Space Mission Concepts
Advanced mission studies are the first step in determining the feasibility of a given space exploration concept. A space scientist develops a science goal in the exploration of space. This may be a new observation method, a new instrument or a mission concept to explore a solar system body. In order to determine the feasibility of a deep space mission, a concept study is convened to determine the technology needs and estimated cost of performing that mission. Heuristics are one method of defining viable mission and systems architectures that can be assessed for technology readiness and cost. Developing a viable architecture depends to a large extent upon extending the existing body of knowledge, and applying it in new and novel ways. These heuristics have evolved over time to include methods for estimating technical complexity, technology development, cost modeling and mission risk in the unique context of deep space missions. This paper examines the processes involved in performing these advanced concepts studies, and analyzes the application of heuristics in the development of an advanced in-situ planetary mission. The Venus Surface Sample Return mission study provides a context for the examination of the heuristics applied in the development of the mission and systems architecture. This study is illustrative of the effort involved in the initial assessment of an advance mission concept, and the knowledge and tools that are applied.
Nilsen, Erik N.↗
Using computer graphics to enhance astronaut and systems safety
Computer graphics is being employed at the NASA Johnson Space Center as a tool to perform rapid, efficient and economical analyses for man-machine integration, flight operations development and systems engineering. The Operator Station Design System (OSDS), a computer-based facility featuring a highly flexible and versatile interactive software package, PLAID, is described. This unique evaluation tool, with its expanding data base of Space Shuttle elements, various payloads, experiments, crew equipment and man models, supports a multitude of technical evaluations, including spacecraft and workstation layout, definition of astronaut visual access, flight techniques development, cargo integration and crew training. As OSDS is being applied to the Space Shuttle, Orbiter payloads (including the European Space Agency's Spacelab) and future space vehicles and stations, astronaut and systems safety are being enhanced. Typical OSDS examples are presented. By performing physical and operational evaluations during early conceptual phases. supporting systems verification for flight readiness, and applying its capabilities to real-time mission support, the OSDS provides the wherewithal to satisfy a growing need of the current and future space programs for efficient, economical analyses.
Computer Simulation↗
Fiber Optic Wing Shape Sensing on NASA's Ikhana UAV
This document discusses the development of fiber optic wing shape sensing on NASA's Ikhana vehicle. The Dryden Flight Research Center's Aerostructures Branch initiated fiber-optic instrumentation development efforts in the mid-1990s. Motivated by a failure to control wing dihedral resulting in a mishap with the Helios aircraft, new wing displacement techniques were developed. Research objectives for Ikhana included validating fiber optic sensor measurements and real-time wing shape sensing predictions; the validation of fiber optic mathematical models and design tools; assessing technical viability and, if applicable, developing methodology and approaches to incorporate wing shape measurements within the vehicle flight control system; and, developing and flight validating approaches to perform active wing shape control using conventional control surfaces and active material concepts.
Richards, Lance↗
Real-time In-Flight Strain and Deflection Monitoring with Fiber Optic Sensors
This viewgraph presentation reviews Dryden's efforts to develop in-flight monitoring based on Fiber Optics. One of the motivating factors for this development was the breakup of the Helios aircraft. On Ikhana the use of fiber optics for wing shape sensing is being developed. They are being used to flight validate fiber optic sensor measurements and real-time wing shape sensing predictions on NASA's Ikhana vehicle; validate fiber optic mathematical models and design tools; Assess technical viability and, if applicable, develop methodology and approach to incorporate wing shape measurements within the vehicle flight control system, and develop and flight validate advanced approaches to perform active wing shape control.
Richards, Lance↗
Overview of International Space Standards
This presentation reviews space standards as put forth by the International Organization for Standardization, additionally the organizational structure for both the international and US groups are presented. A new technical committee for space is proposed, areas of technical coverage are highlighted and models of space communications protocol and space link access service are presented.
spaceport data communications↗
Thermal Soak Analysis of Earth Entry Vehicles
The Multi-Mission Earth Entry Vehicle project is developing an integrated tool called Multi Mission System Analysis for Planetary Entry Descent and Landing that will provide key technology solutions including mass sizing, aerodynamics, aerothermodynamics, and thermal and structural analysis for any given sample return mission. Thermal soak analysis and temperature predictions of various components including the payload container of the entry vehicle are part of the solution that this tool will offer to mission designers. The present paper focuses on the thermal soak analysis of an entry vehicle design based on the Mars Sample Return entry vehicle geometry and discusses a technical approach to develop parametric models for thermal soak analysis that will be integrated into the tool.
Agrawal, Parul↗