Optimization of CubeSat System-Level Design and Propulsion Systems for Earth-Escape Missions

Abstract

Small spacecraft can now perform trajectory maneuvers resulting in significant orbit changes that were once only feasible with larger spacecraft due to the development of miniaturized propulsion technology. This paper addresses the feasibility of using CubeSat Ambipolar Thruster, a large miniaturized propulsion system for constellation control, Earth escape, and planetary flybys, to enable Earth-escape maneuvers on a CubeSat form factor. Operational and trajectory variables include the power setting during thrust maneuvers, when to thrust, and the attitude control inputs. The dynamic energy available through the maneuvers, which is constrained by the power available from the sun depending on the orbit and is consumed in propulsion, is modeled as well as attitude control maneuvers and realistic battery degradation. To explore the design space of this capability, the sensitivity of solutions to spacecraft mass, fuel quantity, initial orbit, solar power collection, and battery size is demonstrated. Optimal orbit-raising techniques are compared and the optimal approach depending on the goals is discussed (i.e., minimize time, minimize fuel, minimize batteries, minimize propulsion system volume, and minimize accumulated radiation). The models and results presented lay the groundwork for future work in integrated vehicle and operational design optimization problems with both interplanetary and constellation architectures.