Design and analysis of a stage-based electrospray propulsion system for CubeSats

Abstract

The standardization of small spacecraft through CubeSats has allowed for more affordable space exploration. This progress in affordability has been limited to Earth orbit due in part to the lack of high [delta]V propulsion systems that are compatible with the small form factor. The ion Electrospray Propulsion System developed at the Space Propulsion Laboratory at the Massachusetts Institute of Technology is a promising technology foundation for a compact, high [delta]V propulsion system. However, the [delta]V output of the propulsion system is limited by the lifetime of individual electrospray thrusters. This thesis presents the design and analysis of a stage-based concept for the ion Electrospray Propulsion System where the propulsion system is composed of a stack of electrospray thruster arrays. The stage-based propulsion system bypasses the lifetime limit of individual electrospray thrusters in order to increase the lifetime of the entire propulsion system. In effect, propulsion capabilities for CubeSats can be advanced without the need for technological developments. With the current performance metrics of the ion Electrospray Propulsion System, deep-space missions with an initial spacecraft form factor of a 3U CubeSat are feasible with current propulsion technology. Mechanisms required for the stage-based system are designed and demonstrated in a vacuum environment. In addition, analytical methodologies for the analysis of stage-based propulsion systems are developed to assist in preliminary mission design as well as provide the framework for autonomous decision making. Finally, applications of a stage-based propulsion system for missions to near-Earth asteroids are explored as well as analytical guidance for the escape trajectory.