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Techniques for Conducting Effective Concept Design and Design-to-Cost Trade Studies

Concept design plays a central role in project success for space missions, as the product of concept design effectively locks in the majority of system lifecycle cost. It involves a concurrent investigation of requirements and multiple mission characteristics such as flight dynamics, design, performance, concept of operations, technology, verification approach, launch and ground interfaces, cost, schedule, and risk.

Posted in: Briefs, Electronics & Computers, Information Sciences, Software, Life cycle analysis, Cost analysis, Systems engineering

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HyDE Model-Based Diagnosis Engine for Stochastic Hybrid Systems

Model-based diagnosis deals with the problem of diagnosing faults in systems using a model of the system for guidance. This problem is complicated by the presence of hybrid dynamics in the system (continuous evolution of the system interspersed with discrete events like commands to change configuration), as well as uncertainties in the form of model approximations and sensor noise. Several model-based technologies have been developed and successfully demonstrated using discrete abstractions of the system as models. These techniques are severely restricted in model expressiveness due to the discrete nature of the models. Moreover, sophisticated model abstraction techniques, as well as algorithms to convert continuous data to discrete form, need to be developed for such an approach to work. Recently, there have been efforts to develop diagnostic engines for hybrid and stochastic systems. However, these techniques have either focused on parametric faults, or use a probabilistic approach to fault identification. Consistency-based approaches that have been successfully demonstrated using discrete models have not been extended to work with stochastic and hybrid models.

Posted in: Briefs, Electronics & Computers, Information Sciences, Software, Computer simulation, Failure analysis, Scale models, Diagnostics

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Scalable and Tileable Aggregate Low-Level Summary Display for Deep Space Network Link Control Tasks

This innovation features critical pieces of information in a single display.The Deep Space Network (DSN) is a collection of three sites around the globe. The positioning of the sites, 120° longitude apart, allows at least one site to see every patch of sky at all times, thus facilitating continuous coverage for any deep space spacecraft that partners with the DSN.

Posted in: Briefs, Software, Data exchange, Surveillance, Displays, Satellites

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Mission Service Architecture Framework (MSAF)

MSAF provides a common framework for designing a Mission Operations System (MOS) based on a control systems paradigm.The representation of mission operations systems (MOS) has been unique to each mission, although there are many common concerns that need to be addressed. A consistent approach and language are needed for representing mission operations systems. The Mission Service Architecture Framework (MSAF) is a foundational extension of SysML and BPMN that provides stereotypes, relationships, and architectural system views that are used to describe mission operations systems.

Posted in: Briefs, Software, Architecture, Flight management systems, Terminology

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Multi-Mission Operations System (MMOS)

MMOS provides a reference design for a Mission Operations System (MOS) and facilitates adaptation to meet mission-specific needs.Each mission needs to develop a Mission Operations System (MOS). Without a standard design to use as a reference, system engineers typically look to a subset of previous missions and develop a system with a mix of heritage, new design, and in some cases, reinvention of existing capabilities. If a reference design were available, mission operations engineers would be able to begin with that reference and add or modify only those portions needed to fulfill a mission’s unique requirements.

Posted in: Briefs, Software, Architecture, Flight management systems, Standardization, Systems engineering, Spacecraft

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Study of Formulating Conserved Scalar Equations for Turbulent Reactive Flows with General Species Mass- Diffusion Coefficients for Utilization in Flamelet Models

The modeling of turbulent reactive flows is a subject of contemporary research. Current turbulent-reaction models cannot account for realistic complexities such as distinct species mass-diffusion coefficients. Under the assumption of a single, constant, mass-diffusion coefficient, a conserved-scalar equation is typically derived in turbulent reactive flows by taking the difference between chemical-species conservation equations having opposite reaction rates (in the sense that the reactant has an opposite reaction rate to the product), thereby creating an equation devoid of reaction terms. Assuming the reaction regions are very thin and are merely contorted by turbulence, chemistry and turbulence can be decoupled, and the evolving statistics of the conserved scalar describe the reaction progression. No such equation has yet been derived for distinct mass-diffusion coefficient cases where the single coefficient is now replaced by a full matrix. Considering that mass diffusion is responsible for reactants approaching at the molecular level and for reaction initiation, this lack of mathematical framework is very disturbing.

Posted in: Briefs, Software, Computational fluid dynamics, Mathematical models, Turbulence

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HORIZON Framework for Distributed Data Management and Product Generation Workflow

The NASA Earth Observing System Data and Information System (EOSDIS) is a data-centric system designed for the processing and archiving from NASA’s Earth Observation missions and their distribution, as well as provision of specialized services to users. The major components of EOSDIS are 12 Distributed Active Archive Centers (DAACs), 14 Science Investigator-led Processing Systems (SIPSs), and the EOS Clearing House (ECHO). The DAACs play an import role within EOSDIS. They are divided by discipline with User Working Groups (UWGs) tailored to mission and objectives of the DAAC.

Posted in: Briefs, Software, Architecture, Data management, Logistics

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