VLSI Design and Embedded Systems Group

Distributed computing in satellite constellations

There is a continuing trend in the space community to reduce costs involved in space missions. Miniaturization has been the primary method that was deployed for reducing space mission costs. This is now changing, due to the recent advancements in technology that enable advanced mission architectures namely, distributed spacecraft missions. Several spacecraft flying in close formations would collaboratively achieve the mission aims at lower costs and with enhanced reliability compared to larger single platform missions. While research in the area of formation flying is quite active in technologies that are key to the success of such missions, such as the development of efficient control algorithms, reliable inter-satellite links and precise navigational techniques, other areas are dealt with to a much lesser extent. In this research work we exploit the utilisation of the spatially distributed nature of formation flying missions in forming a distributed computing system over the inter-satellite network.

Distributed computing is a very active, continuously developing area of research, fuelled by the ever-increasing computing power and developments in networking. Several fields have emerged from distributed computing including cluster computing, distributed embedded systems and more recently wireless sensor networks and ubiquitous computing.

Most modern missions use a real-time operating system (RTOS) that allows a form of loosely coupled distributed computing. We are currently developing a novel middleware on top of an RTOS to enable tighter coupling between the nodes in the distributed system. The middleware design takes into consideration factors that are including formation flying dynamics, unreliable inter-satellite links and highly constrained nodes (in terms of mass and power). Design requirements include scalability, fault-tolerance, low-power, low memory (both static and dynamic) requirements and real-time performance.

Publications:

A.-H. Jallad and T. Vladimirova. Distributed Computing for Formation Flying Missions - accepted for the ACS/IEEE International Conference on Computer Systems and Applications, AICCSA-06, 8-11 March 2006, Dubai/Shariah, UAE.

A.-H. Jallad and T. Vladimirova. Operating Systems for Wireless Sensor Networks in Space - Proceedings of the 8th Military and Aerospace Applications of Programmable Logic Devices and Technologies International Conference (MAPLD'2003), P-1005, September 7-9, 2005, Washington DC, US, NASA.