Formation flying experiments on the orion-emerald mission

This paper presents an update on the Orion-Emerald mission. This mission has been designed to demonstrate several key technologies required for formation flying, which is an important component of many planned space missions, including space-based radar and interferometry. As such, this mission represents an essential step towards a new space mission paradigm in which a "virtual spacecraft bus" is created using several smaller spacecraft. This new approach should provide improved science, enhanced reliability, and reduced mission cost. The primary goal of the Orion-Emerald mission is to demonstrate solutions to the relative navigation and control problems associated with flying spacecraft in a tight, closely-spaced formation. The mission will use carrierphase differential GPS (CDGPS) as the primary relative navigation sensor. Algorithms for fuel optimization and formation planning have also been developed and these will be executed onboard. Because of the poor visibility available to ground stations, the entire navigation and control system is being designed to function autonomously on-orbit. This paper provides an update on the status of the vehicle and software developments for this very challenging microsatellite mission. l