Satellite architecture [for autonomous on-orbit servicing]

This paper describes an effort to develop an avionics architecture that enables replacement of deficient satellite hardware on-orbit as well as upgrade/adapt on-orbit systems. It is anticipated that routine, safe, and reliable spacecraft servicing will have significant payoff for many future types of science and military missions. Satellites that are placed on-orbit and are functionally lost due to simple failures beg for the development of an on-orbit replacement capability. To date, this has been performed by an astronaut. Human intervention in space, however, carries risk and cost associated with it that would not be necessary if an autonomous satellite repair capability was developed. The associated capability to perform pre-planned upgrades and adaptations to on-orbit space assets also has the potential for architecting high performance future spacecraft. The first step in developing a serviceable satellite is to evolve the tightly integrated satellite architectures of today toward an architecture that supports functional and/or physical replacement of anomalous or failed hardware. Draper Laboratory has performed a trade study to develop a single-point architecture that provides a growth path from the functionally efficient satellite designs of today to a functionally reliable modular architecture that will support the autonomous on-orbit upgrade and functional enhancement of tomorrow's satellites. This paper presents an overview of an architecture that can enable autonomous satellite servicing.