A study of the selection of microcomputer architectures to automate planetary spacecraft power systems

Performance and reliability models of alternate microcomputer architectures as a methodology for optimizing system design were examined. A methodology for selecting an optimum microcomputer architecture for autonomous operation of planetary spacecraft power systems was developed. Various microcomputer system architectures are analyzed to determine their application to spacecraft power systems. It is suggested that no standardization formula or common set of guidelines exists which provides an optimum configuration for a given set of specifications

An On-line BIST RAM Architecture with Self Repair Capabilities

The emerging field of self-repair computing is expected to have a major impact on deployable systems for space missions and defense applications, where high reliability, availability, and serviceability are needed. In this context, RAM (random access memories) are among the most critical components. This paper proposes a built-in self-repair (BISR) approach for RAM cores. The proposed design, introducing minimal and technology-dependent overheads, can detect and repair a wide range of memory faults including: stuck-at, coupling, and address faults. The test and repair capabilities are used on-line, and are completely transparent to the external user, who can use the memory without any change in the memory-access protocol. Using a fault-injection environment that can emulate the occurrence of faults inside the module, the effectiveness of the proposed architecture in terms of both fault detection and repairing capability was verified. Memories of various sizes have been considered to evaluate the area-overhead introduced by this proposed architectur

First Lunar Outpost support study

The First Lunar Outpost (FLO) is the first manned step in the accomplishment of the Space Exploration Initiative, the Vice President's directive to NASA on the 20th anniversary of the Apollo moon landing. FLO's broad objectives are the establishment of a permanent human presence on the moon, supporting the utilization of extraterrestrial resources in a long-term, sustained program. The primary objective is to emplace and validate the first elements of a man tended outpost on the lunar surface to provide the basis for: (1) establishing, maintaining and expanding human activities and influence across the surface; (2) establishing, maintaining and enhancing human safety and productivity; (3) accommodating space transportation operations to and from the surface; (4) accommodating production of scientific information; (5) exploiting in-situ resources. Secondary objectives are: (1) to conduct local, small scale science (including life science); (2) In-situ resource utilization (ISRU) demonstrations; (3) engineering and operations tests; (4) to characterize the local environment; and (5) to explore locally. The current work is part of ongoing research at the Sasakawa International Center for Space Architecture supporting NASA's First Lunar Outpost initiative. Research at SICSA supporting the First Lunar Outpost initiative has been funded through the Space Exploration Initiatives office at Johnson Space Center. The objectives of the current study are to further develop a module concept from an evaluation of volumetric and programmatic requirements, and pursue a high fidelity design of this concept, with the intention of providing a high fidelity design mockup to research planetary design issues and evaluate future design concepts

Survey of Inter-satellite Communication for Small Satellite Systems: Physical Layer to Network Layer View

Small satellite systems enable whole new class of missions for navigation, communications, remote sensing and scientific research for both civilian and military purposes. As individual spacecraft are limited by the size, mass and power constraints, mass-produced small satellites in large constellations or clusters could be useful in many science missions such as gravity mapping, tracking of forest fires, finding water resources, etc. Constellation of satellites provide improved spatial and temporal resolution of the target. Small satellite constellations contribute innovative applications by replacing a single asset with several very capable spacecraft which opens the door to new applications. With increasing levels of autonomy, there will be a need for remote communication networks to enable communication between spacecraft. These space based networks will need to configure and maintain dynamic routes, manage intermediate nodes, and reconfigure themselves to achieve mission objectives. Hence, inter-satellite communication is a key aspect when satellites fly in formation. In this paper, we present the various researches being conducted in the small satellite community for implementing inter-satellite communications based on the Open System Interconnection (OSI) model. This paper also reviews the various design parameters applicable to the first three layers of the OSI model, i.e., physical, data link and network layer. Based on the survey, we also present a comprehensive list of design parameters useful for achieving inter-satellite communications for multiple small satellite missions. Specific topics include proposed solutions for some of the challenges faced by small satellite systems, enabling operations using a network of small satellites, and some examples of small satellite missions involving formation flying aspects.Comment: 51 pages, 21 Figures, 11 Tables, accepted in IEEE Communications Surveys and Tutorial

Space station needs, attributes and architectural options study. Volume 1: Executive summary

Planetary explorations, Earth observations, space physics, astronomy-astrophysics, solar physics, life/biological/medical sciences, materials processing in space, communications, and technology development are addressed. Mission requirements, integrated user requirements, and space station user accommodation requirements are discussed. Mission implementation concepts and cost, benefits and programmatic analysis are discussed

How to Extend the Capabilities of Space Systems for Long Duration Space Exploration Systems

For sustainable Exploration Missions the need exists to assemble systems-of-systems in space, on the Moon or on other planetary surfaces. To fulfill this need new and innovative system architecture is needed that can be satisfied with the present lift capability of existing rocket technology without the added cost of developing a new heavy lift vehicle. To enable ultra-long life missions with minimum redundancy and lighter mass the need exists to develop system soft,i,are and hardware reconfigurability, which enables increasing functionality and multiple use of launched assets while at the same time overcoming any components failures. Also the need exists to develop the ability to dynamically demate and reassemble individual system elements during a mission in order to work around failed hardware or changed mission requirements. Therefore to meet the goals of Space Exploration Missions in hiteroperability and Reconfigurability, many challenges must be addressed to transform the traditional static avionics architecture into architecture with dynamic capabilities. The objective of this paper is to introduce concepts associated with reconfigurable computer systems; review the various needs and challenges associated with reconfigurable avionics space systems; provide an operational example that illustrates the needs applicable to either the Crew Exploration Vehicle or a collection of "Habot like" mobile surface elements; summarize the approaches that address key challenges to acceptance of a Flexible, Intelligent, Modular and Affordable reconfigurable avionics space system

An Autonomous Surface Vehicle for Long Term Operations

Environmental monitoring of marine environments presents several challenges: the harshness of the environment, the often remote location, and most importantly, the vast area it covers. Manual operations are time consuming, often dangerous, and labor intensive. Operations from oceanographic vessels are costly and limited to open seas and generally deeper bodies of water. In addition, with lake, river, and ocean shoreline being a finite resource, waterfront property presents an ever increasing valued commodity, requiring exploration and continued monitoring of remote waterways. In order to efficiently explore and monitor currently known marine environments as well as reach and explore remote areas of interest, we present a design of an autonomous surface vehicle (ASV) with the power to cover large areas, the payload capacity to carry sufficient power and sensor equipment, and enough fuel to remain on task for extended periods. An analysis of the design and a discussion on lessons learned during deployments is presented in this paper.Comment: In proceedings of MTS/IEEE OCEANS, 2018, Charlesto

Real Options in Enterprise Architecture: A Holistic Mapping of Mechanisms and Types for Uncertainty Management

Uncertaintymanagement is crucial for achieving high performance in enterprises that develop or operate complex engineering systems. This study focuses on flexibility as a means of managing uncertainties and builds upon real options analysis (ROA) that provides a foundation for quantifying the value of flexibility. ROA has found widespread applications ranging from strategic investments to product design. However, these applications are often isolated to specific domains. Furthermore, ROA is focused on valuation, rather than the identification of real options. In this paper, we introduce a framework for holistic consideration of real options in an enterprise context. First, to enable a holistic approach, we use a generalized enterprise architecture framework that considers eight views: strategy, policy, organization, process, product, service, knowledge, and information technology (IT). This expands upon the classical IT-centric view of enterprise architecture. Second, we characterize a real option as a mechanism and type. This characterization disambiguates among mechanisms that enable flexibility and types of flexibility to manage uncertainties. Third, we propose mapping of mechanisms and types to the enterprise architecture views.We leverage this mapping in an integrated real options framework and demonstrate its benefit over the traditional localized approach to ROA.Singapore. Defence Science & Technology AgencySingapore. DSO National Laboratorie