Evaluation of propulsion options for interstellar missions

Abstract

This paper describes an evaluation of various propulsion options for robotic interstellar rendezvous missions to stars ranging from 4.5 Light Years (L.Y.) with a 10-year trip time, to 40 L.Y. with a 100-year trip time. Concepts considered included advanced electric propulsion, nuclear (fission, fusion, antimatter) propulsion, beamed energy (e.g., light sails, MagSails) propulsion, electromagnetic catapults, in-situ propellant production concepts (e.g., the interstellar ramjet), and hybrid systems (e.g., antimatter-catalyzed fission/ fusion). The various candidate propulsion options were evaluated using three screening criteria. First, is it possible for the candidate system to achieve the required AV, which can be as much as 0.6 c for a fast, 4.5-L.Y. mission. Second, does the propulsion systems require an extensive, mission-unique supporting infrastructure. Finally, the technology readiness levels of the various subsystem technologies of the propulsion concept are reviewed. This screening process resulted in the selection of beamed energy sail, matter-antimatter, and fusion ramjet concepts as the most promising candidates. Potential mission performance and near-term technology goals of these concepts were then evaluated.