Electric Propulsion Options for Cubesats

The CubeSat platform is presently well established as a standard building block for nano-satellites and presents a large potential for a number of applications, particularly in its 3U (or larger) version. The aim of this study is to investigate the possibilities offered by the implementation of Electric Propulsion (EP) on CubeSat platforms and to analyse the relative advantages of several current EP technologies with respect to specific constraints of such minimal spacecraft. We focus on devices requiring limited power and with small mass and size, yet performing at relatively high specific impulse, such as Hall Effect Thrusters, Field Emission Electric Propulsion, Pulsed Plasma Thrusters and resistojets. Performance analysis is performed first analytically, then by direct simulation of representative mission profiles on Alta's SATSLAB simulator, whereby the coupled effect of orbit, attitude and onboard energy management is accounted for. We show that performance of CubeSats is significantly enhanced by a properly chosen EP system, extending the operational envelope to include manoeuvres such as residual drag compensation, change of orbital altitude and plane inclination, and rephasing in constellations, resulting in additional mission profile flexibility. New mission classes, enabled by the unique combination of CubeSat's tiny mass and EP manoeuvring capability, are outlined and discussed