Multimode Propulsion: Cislunar Rideshare Mission Concept Trade Space Analysis for Small Spacecraft

Multimode propulsion offers the promise of space-craft equipped with a high-thrust chemical maneuver mode and a solar electric low-thrust maneuver mode. As national and commercial activity in cislunar space increases, new low-cost pathways for small spacecraft to access multi-body orbits can be explored. One pathway of key interest is the available excess payload capacity on launch systems and transfer stages designed to deliver landers to the lunar surface, such as those on the Commercial Lunar Payload Services (CLPS) missions [1]. To allow for flexibility in mission Concept of Operations (CONOPS), enable rapid-response mission timelines, and provide an examination of the design trade space for low-cost rideshare missions to cislunar space, this paper proposes a set of new preliminary mission concepts that utilize current CubeSat technology enhanced with multimode propulsion. The proposed mission concepts are designed around deployment from future rideshare opportunities to the lunar surface, aiming to deliver a 16U CubeSat to an Earth-Moon L2 Near Rectilinear Halo Orbit (NRHO). This study and resulting analysis find that the mul-timode system shows promising characteristics for enhancing flexibility in mission CONOPS. These include reduced transfer time, increased robustness to schedule changes and mission anomalies, and the ability to target powered lunar flybys. This work culminates in an overview of the low-cost cislunar mission concept trade space for small spacecraft utilizing future mul-timode propulsion systems. The principal results of this study consist of an analysis that trades time of flight (TOF) against the amount of propellant consumed across different families of multimode transfers. These families represent different sets of possible mission CONOPS with desirable attributes such as reduced time of flight or reduced propellant cost compared to baseline chemical-only missions. These results are presented to inform future mission formulation studies on low-cost cislunar missions and showcase the ability of multimode propulsion to enhance future mission concepts.