A software platform for fractionated spacecraft

Abstract

Abstract-A fractionated spacecraft is a cluster of independent modules that interact wirelessly to maintain cluster flight and realize the functions usually performed by a monolithic satellite. This spacecraft architecture poses novel software challenges because the hardware platform is inherently distributed, with highly fluctuating connectivity among the modules. It is critical for mission success to support autonomous fault management and to satisfy real-time performance requirements. It is also both critical and challenging to support multiple organizations and users whose diverse software applications have changing demands for computational and communication resources, while operating on different levels and in separate domains of security.The solution proposed in this paper is based on a layered architecture consisting of a novel operating system, a middleware layer, and component-structured applications. The operating system provides primitives for concurrency, synchronization, and secure information flows; it also enforces application separation and resource management policies. The middleware provides higher-level services supporting request/response and publish/subscribe interactions for distributed software. The component model facilitates the creation of software applications from modular and reusable components that are deployed in the distributed system and interact only through well-defined mechanisms.Two cross-cutting aspects -multi-level security and multilayered fault management -are addressed at all levels of the architecture. The complexity of creating applications and performing system integration is mitigated through the use of a domain-specific model-driven development process that relies on a dedicated modeling language and its accompanying graphical modeling tools, software generators for synthesizing infrastructure code, and the extensive use of model-based analysis for verification and validation.

Integrated Analysis of Temporal Behavior of Component-Based Distributed Real-Time Embedded Systems

“…The target architecture for timing analysis is DREMS [23], [14]. DREMS was designed and developed for a class of distributed real-time embedded systems that are remotely managed and have strict timing requirements.…”

“…DREMS is a software infrastructure for the design, implementation, deployment, and management of component-based real-time embedded systems. The infrastructure includes design-time modeling tools [24] that integrate with a well-defined and fully implemented component model [25], [13] used to build component-based applications. Rapid prototyping and code generation features coupled with a modular run-time platform automate tedious aspects of software development and enable robust deployment and operation of mixed-criticality distributed applications.…”

Real-time fault tolerant deployment and configuration framework for cyber physical systems

“…Our ongoing work focuses on supporting these key requirements within the LE-DAnCE framework and is evaluated in the context of fractionated spacecrafts [2], which is a representative CPS that brings new challenges to an already hard set of problems. For example, in our prior work on LE-DAnCE we had assumed stable networks.…”

Towards a resilient deployment and configuration infrastructure for fractionated spacecraft

“…1 Explicitly defining all possible sequences of fault events and the corresponding reconfiguration actions is both cumbersome and error-prone, especially for large systems. Implicit encoding [16], [11], is centered around a functional model, created at designtime, that describes the required functionality of the system in terms of the component configurations required to provide that functionality.…”

“…INTRODUCTION System F6 [1] (F6 stands for Future, Fast, Flexible, Fractionated, Free-Flying spacecraft) is a highly resourceconstrained, dynamic system which consists of a cluster of satellites forming the 'fractionated spacecraft', which provides a distributed computing platform in space. Each satellite module communicates wirelessly with others in the same cluster and with resources located on the ground.…”