A SELF-ADAPTIVE DATA HANDLING SYSTEM FOR SMALL SATELLITES AND ITS IMPACT ON FUTURE SATELLITE OPERATIONS

摘要

The work in this project is part of PolyOrbite's satellite design with the goal to build and launch Québec's first student made satellite. PolyOrbite is a technical student society at Polytechnique Montréal and designs a 2U CubeSat to demonstrate self-adaptive systems for spacecraft. The aim of the satellite is to show the benefits of self-adaptivity on two payloads: a self-adaptive data handling system (DHS) and a self-adaptive green house. In this paper, we present the self-adaptive DHS and discuss its potential impact on future satellite operations. In recent years, we have seen a fair amount of research focusing on software libraries and frameworks for self-awareness. Despite existing works, there is no official framework available that takes into account the characteristics of space systems, and their strict need for real-time and fault-tolerance. We discuss tools and techniques necessary for the implementation of a self-adaptive computing system for aerospace. Our system-capable of adaptation-deals with uncertain environments, heterogeneous resources, and irregular workloads, while taking into account housekeeping (e.g. power consumption, attitude control) and scientific, payload related tasks. We address several challenges as why to implement reconfigurable systems with self-adaptive capabilities: programmers have to deal with the advent of multi-core systems, which made the task of writing solid codc much more complicated than it was for single-core systems; this code should achieve desired levels of quality of service (QoS) in multiple scenarios that might not be known a priori; moreover, the same code is required to run on multiple architectures, possibly with some degree of performance guarantees on each one of them. The complexity of all these tasks is skyrocketing and it is impossible, or too expensive, to find programmers having such strong competences both in software design and in architccture-related issues. Therefore, the best way to deal with th