Pluto Orbiter–Kuiper Belt Explorer: Mission Design for the Gold Standard

A mission design study was conducted demonstrating for the first time the feasibility of a combined Pluto orbiter–Kuiper Belt explorer mission using present-day electric propulsion (EP) performance and launch vehicles, assuming that radioisotope thermoelectric generator (RTG)–sourced electricity would power the EP system, a not-yet-demonstrated but low-risk capability. This mission breaks the scientific conundrum between desires to study the Pluto system in more detail using an orbiter and desires to reconnoiter other bodies in the Kuiper Belt. This study also includes the first demonstration that a wide suite of Pluto orbiter scientific objectives can be accomplished with an orbital trajectory primarily using Charon gravity-assist maneuvers to maneuver in the system. The study further demonstrates that Pluto system escape back into the Kuiper Belt can be accomplished using Charon gravity assists, thereby further reducing onboard propulsion requirements. The primary technical challenges for this mission are the long (75 years) mission duration imposed by current-day RTG nuclear systems required to power the spacecraft and its EP system, and the need for high-bit-rate communications to make the Pluto orbiter continuously effective. As discussed in this study, the communications challenges can be overcome without new systems developments or unreasonable mass challenges. More reasonable mission durations (e.g., ) will require the development of multi-kilowatt nuclear fission reactor power generation systems; still shorter mission durations require both more power and higher EP thrust, as in multiple electric engines operating simultaneously.