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Java Library for Input and Output of Image Data and Metadata

A Java-language library supports input and output (I/O) of image data and metadata (label data) in the format of the Video Image Communication and Retrieval (VICAR) image-processing software and in several similar formats, including a subset of the Planetary Data System (PDS) image file format. The library does the following:

Posted in: Information Sciences, Briefs, TSP

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CLARAty Functional-Layer Software

Functional-layer software for the Coupled Layer Architecture for Robotics Autonomy (CLARAty) is being developed. [CLARAty was described in "Coupled-Layer Architecture for Advanced Software for Robots" (NPO-21218), NASA Tech Briefs, Vol. 26, No. 12 (December 2002), page 48. To recapitulate: CLARAty was proposed to improve the modularity of robotic software while tightening the coupling between planning/execution and control subsystems. Whereas prior robotic software architectures have typically contained three levels, the CLARAty architecture contains two layers: a decision layer and a functional layer.] Just as an operating system provides abstraction from computational hardware, the CLARAty functional-layer software provides for abstraction for the different robotic systems. The functional-layer software establishes interrelated, object-oriented hierarchies that contain active and passive objects that represent the different levels of system abstractions and components. The functional-layer software is decomposed into a set of reusable core components and a set of extended components that adapt the reusable set to specific hardware implementations. The reusable components (a) provide behavior and interface definitions and implementations of basic functionality, (b) provide local executive capabilities, (c) manage local resources, and (d) support state and resource queries by the decision layer. Software for robotic systems can be built by use of these components.

Posted in: Information Sciences, Briefs, TSP

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Software for Building Models of 3D Objects via the Internet

The Virtual EDF Builder (where "EDF" signifies Electronic Development Fixture) is a computer program that facilitates the use of the Internet for building and displaying digital models of three- dimensional (3D) objects that ordinarily comprise assemblies of solid models created previously by use of computer-aided-design (CAD) programs. The Virtual EDF Builder resides on a UNIX- based server computer. It is used in conjunction with a commercially available Web-based plug-in viewer program that runs on a client computer. The Virtual EDF Builder acts as a translator between the viewer program and a database stored on the server. The translation function includes the provision of uniform resource locator (URL) links to other Web-based computer systems and databases. The Virtual EDF builder can be used in two ways: (1) If the client computer is UNIX-based, then it can assemble a model locally; the computational load is transferred from the server to the client computer. (2) Alternatively, the server can be made to build the model, in which case the server bears the computational load and the results are downloaded to the client computer or workstation upon completion.

Posted in: Information Sciences, Briefs, TSP

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Software for Estimating Costs of Testing Rocket Engines

A high-level parametric mathematical model for estimating the costs of testing rocket engines and components at Stennis Space Center has been implemented as a Microsoft Excel program that generates multiple spreadsheets. The model and the program are both denoted, simply, the Cost Estimating Model (CEM). The inputs to the CEM are the parameters that describe particular tests, including test types (component or engine test), numbers and duration of tests, thrust levels, and other parameters. The CEM estimates anticipated total project costs for a specific test. Estimates are broken down into testing categories based on a work-breakdown structure and a cost-element structure. A notable historical assumption incorporated into the CEM is that total labor times depend mainly on thrust levels. As a result of a recent modification of the CEM to increase the accuracy of predicted labor times, the dependence of labor time on thrust level is now embodied in third- and fourth-order polynomials.

Posted in: Information Sciences, Briefs

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Optimization of Orientations of Spacecraft Reaction Wheels

A report presents a method of optimizing the orientations of three reaction wheels used to regulate the angular momentum of a spacecraft. The method yields an orientation matrix that minimizes mass, torque, and power demand of the reaction wheels while maximizing the allowable duration between successive angular-momentum dumps. Each reaction wheel is parameterized with its own unit vector, and a quadratic cost function is defined based on requirements for torque, storage of angular momentum, and power demand. Because management of angular momentum is a major issue in designing and operating an orbiting spacecraft, an angular-momentum-management strategy is parameterized and included as part of the overall optimization process. The report describes several case studies, including one of a spacecraft proposed to be placed in orbit around Europa (the fourth largest moon of Jupiter).

Posted in: Mechanical Components, Briefs, TSP

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Analytic Method for Computing Instrument Pointing Jitter

Jitter can be computed more efficiently. A new method of calculating the root-mean-square (rms) pointing jitter of a scientific instrument (e.g., a camera, radar antenna, or telescope) is introduced based on a state-space concept. In comparison with the prior method of calculating the rms pointing jitter, the present method involves significantly less computation.

Posted in: Information Sciences, Briefs, TSP

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Deforming Fibrous Insulating Tiles To Fit Curved Surfaces

Flat billets are heated and pressed gently against curved mold surfaces. A curved tile of refractory silica-fiber-based or alumina-fiber-based thermal-insulation material can be formed from an initially flat billet in a process that includes pressing against a curved mold surface during heating. The mold or tile curvature can be concave or convex. Curved tiles are needed for thermal protection of curved surfaces of spacecraft reentering the terrestrial atmosphere; curved thermal-protection tiles may also be useful on Earth in some industrial applications.

Posted in: Manufacturing & Prototyping, Briefs, TSP

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