A New Approach to Memory Partitioning in On-board Spacecraft Software. In Fabrice Kordon and Tullio Vardanega (eds.), Reliable Software Technologies

The current trend to use partitioned architectures in on-board spacecraft software requires applications running on the same computer platform to be isolated from each other both in the temporal and memory domains. Memory isolation techniques currently used in Integrated Modular Avionics for Aeronautics usually require a Memory Management Unit (MMU), which is not commonly available in the kind of processors currently used in the Space domain. Two alternative approaches are discussed in the paper, based on some features of Ada and state-of-the art compilation tool-chains. Both approaches provide safe memory partitioning with less overhead than current IMA techniques. Some footprint and performance metrics taken on a prototype implementation of the most flexible approach are included

Autonomous spacecraft maintenance study group

A plan to incorporate autonomous spacecraft maintenance (ASM) capabilities into Air Force spacecraft by 1989 is outlined. It includes the successful operation of the spacecraft without ground operator intervention for extended periods of time. Mechanisms, along with a fault tolerant data processing system (including a nonvolatile backup memory) and an autonomous navigation capability, are needed to replace the routine servicing that is presently performed by the ground system. The state of the art fault handling capabilities of various spacecraft and computers are described, and a set conceptual design requirements needed to achieve ASM is established. Implementations for near term technology development needed for an ASM proof of concept demonstration by 1985, and a research agenda addressing long range academic research for an advanced ASM system for 1990s are established

Planning and Resource Management in an Intelligent Automated Power Management System

Power system management is a process of guiding a power system towards the objective of continuous supply of electrical power to a set of loads. Spacecraft power system management requires planning and scheduling, since electrical power is a scarce resource in space. The automation of power system management for future spacecraft has been recognized as an important R&D goal. Several automation technologies have emerged including the use of expert systems for automating human problem solving capabilities such as rule based expert system for fault diagnosis and load scheduling. It is questionable whether current generation expert system technology is applicable for power system management in space. The objective of the ADEPTS (ADvanced Electrical Power management Techniques for Space systems) is to study new techniques for power management automation. These techniques involve integrating current expert system technology with that of parallel and distributed computing, as well as a distributed, object-oriented approach to software design. The focus of the current study is the integration of new procedures for automatically planning and scheduling loads with procedures for performing fault diagnosis and control. The objective is the concurrent execution of both sets of tasks on separate transputer processors, thus adding parallelism to the overall management process

Deep Space Network information system architecture study

The purpose of this article is to describe an architecture for the Deep Space Network (DSN) information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990s. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies, such as the following: computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control

Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC), version 4.0: User's manual

The information in the NASARC (Version 4.0) Technical Manual (NASA-TM-101453) and NASARC (Version 4.0) User's Manual (NASA-TM-101454) relates to the state of Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC) software development through November 1, 1988. The Technical Manual describes the NASARC concept and the algorithms used to implement the concept. The User's Manual provides information on computer system considerations, installation instructions, description of input files, and program operation instructions. Significant revisions were incorporated in the Version 4.0 software over prior versions. These revisions have further enhanced the modeling capabilities of the NASARC procedure and provide improved arrangements of predetermined arcs within the geostationary orbit. Array dimensions within the software were structured to fit within the currently available 12-megabyte memory capacity of the International Frequency Registration Board (IFRB) computer facility. A piecewise approach to predetermined arc generation in NASARC (Version 4.) allows worldwide planning problem scenarios to be accommodated within computer run time and memory constraints with enhanced likelihood and ease of solution

Integration and validation of embedded flight software on space-qualified multicore architectures

In the recent decades, the importance of software on space missions has notably increased, reflecting the need to integrate advanced on-board functionalities. With multicore processors being lately introduced to host critical high-performance applications, the complexity to validate software has significantly raised with respect to single core architectures. While there has been a big step forward in avionics after the publication of the CAST-32A paper, the ECSS-E-ST-40C software engineering standard used by the European Space Agency (ESA) is still not providing validation support for multicore processors. Hence, it is expected that standardising guidelines to develop software on such platforms will become a recurring topic in the industry to match the demands of future space exploration missions

Space Generic Open Avionics Architecture (SGOAA) reference model technical guide

This report presents a full description of the Space Generic Open Avionics Architecture (SGOAA). The SGOAA consists of a generic system architecture for the entities in spacecraft avionics, a generic processing architecture, and a six class model of interfaces in a hardware/software system. The purpose of the SGOAA is to provide an umbrella set of requirements for applying the generic architecture interface model to the design of specific avionics hardware/software systems. The SGOAA defines a generic set of system interface points to facilitate identification of critical interfaces and establishes the requirements for applying appropriate low level detailed implementation standards to those interface points. The generic core avionics system and processing architecture models provided herein are robustly tailorable to specific system applications and provide a platform upon which the interface model is to be applied

Spacecraft Data Handling Architecture based on AFDX network

International audienceThe Mission project (Methodology and assessment for the applicability of ARINC-664 (AFDX)[4] in Satellite/Spacecraft on-board communicatION networks), as an FP7 initiative for bringing terrestrial SME research into the space domain, aims to apply the Integrated Modular Avionics (IMA) concept on spacecraft, together with highly deterministic interconnected on-board network (ARINC-664, AFDX). It will constitute an enabling technology harmonization and standardization action. Together with an intrinsic improvement of systems performance, product assurance and reliability, it is expected to provide multiple benefits at all industrial level such as standardized and configurable systems, products and technology elements, easier and faster integration of complex systems, larger procurement basis, and easier subcontracting scheme. This paper presents the project objectives, architecture design, proof of concept demonstrator and current progress

Multiprocessing techniques for unmanned multifunctional satellites Final report,

Simulation of on-board multiprocessor for long lived unmanned space satellite contro

Development and update of aerospace applications in partitioned architectures

Tese de mestrado em Engenharia Informática, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2011Para enfrentar os desafios e requisitos impostos por missões espaciais futuras, a indústria aeroespacial tem vindo a seguir uma tendência para adoptar arquitecturas computacionais inovadoras e avançadas, cumprindo requisitos estritos de tamanho, peso e consumo energético (SWaP) e assim diminuir o custo total da missão assegurando a segurança na operação e a pontualidade do sistema. A arquitectura AIR (ARINC 653 in Space Real-Time Operating System), desenvolvida para responder ao interesse da indústria aeroespacial, particularmente da Agência Espacial Europeia (ESA), fornece um ambiente compartimentado para o desenvolvimento e execução de aplicações aeroespaciais, seguindo a noção de compartimentação temporal e espacial, preservando os requisitos temporais das aplicações e a segurança na operação. Durante uma missão espacial, a ocorrência de eventos inesperados ou alterações aos planos da missão introduz novas restrições. Assim, é de grande importância ter a possibilidade de alojar novas aplicações na plataforma computacional de veículos espaciais ou modificar aplicações já existentes em tempo de execução e, deste modo, cumprir os novos requisitos ou melhorar as funções do veículo espacial. O presente trabalho introduz na arquitectura AIR o suporte à inclusão e actualização de novas funcionalidades ao plano de missão durante o funcionamento do sistema. Estas funcionalidades podem ser formadas por componentes de software modificados ou pelos requisitos temporais correspondentes. O melhoramento da arquitectura AIR com a possibilidade de realizar actualizações de software requer um ambiente e ferramentas de desenvolvimento adequados. Neste sentido, a metodologia para o desenvolvimento de software em sistemas baseados na arquitectura AIR é revisitada.To face the challenges and requirements imposed by future space missions, the aerospace industry has been following the trend of adopting innovative and advanced computing system architectures fulfilling strict requisites of size, weight and power consumption (SWaP) thus decreasing the mission overall cost and ensuring the safety and timeliness of the system. The AIR (ARINC 653 in Space Real-Time Operating System) architecture has been defined dependent on the interest of the aerospace industry, especially the European Space Agency (ESA). AIR provides a partitioned environment for the development and execution of aerospace applications, based on the idea of time and space partitioning (TSP), aiming the preservation of the application requirements, timing and safety. During a space mission, the occurrence of unexpected events or the change of the mission plans introduces new constraints to the mission. Therefore, it is paramount to have the possibility to host new applications in spacecraft onboard computer platform, or modify the existing ones in execution time, thus fulfilling new requirements or enhancing spacecraft functions. The work described on this thesis introduces in the AIR architecture the support for the inclusion of new features to the mission plan during the system operation. These new features may be composed of modified software components or the corresponding timing requirements. The improvement of the AIR architecture with the ability to perform software updates requires a suitable development environment and tools. Therefore, the methodology for software development in AIR-based systems, regarding the build and integration process, is reexamined