A Scalable Packet Routing Mechanism for Chip-Satellites in Coplanar Orbits

Abstract

This article is motivated by the advent of gram-scale spacecraft, or “chipsats,” which enable satellite networks composed of hundreds of thousands of nodes. Networks of this size necessitate routing policies unlike any that have been used for collections of conventional spacecraft. This article argues which information should and should not be assumed available to each node in such a network. Based on these argued assumptions, this article uses dynamic programming to derive a routing mechanism for planar collections of chipsats. It, then, shows that the resulting mechanism is optimal for collections of orbits that are all near enough in altitude to communicate with one another, and also for collections of circular orbits. This article shows that the derived mechanism is suboptimal for collections of nested, unconnected orbits, and for stochastic collections of unconnected orbits. The particular form of the routing mechanism derived in this article is unique to planar collections of orbits, but the structure of the mechanism generalizes to three dimensions.