Navigation system architecture in spacecraft swarms

Space mission require the implementation of a guidance, navigation and control (GNC) loop, either autonomous or built on remote assets, to correctly attain their goal. The increasing interest for mission architectures inspired by biological systems and based on a large number of elementary agents, typically labelled as swarms, introduces the issue of the identification of the most suitable GNC configuration. This paper explores the problem with specific reference to the navigation function, which is a pre-requisite to a suitable GNC. A simple, upper boundary for acceptable navigation performance in swarms is proposed, and this constraint is therefore considered in different possible exploration scenarios. The navigation options available in each scenario – either autonomous or based on external infrastructures - are then compared with respect to this condition.