A Revisited Analysis of the Radioisotope Sail and Its Possible Application to Relativistic Spaceflight

This study is focused on the development of mathematical models suitable for a broad study of radioisotope sails performance, in particular for materials characterized by alpha decays, both single and multiple. The models have been obtained in the framework of the Special Theory of Relativity, in order to provide mathematical tools suitable for future possible relativistic missions. The mathematical models of different relativistic spaceflight profiles were also studied and their compatibility with the radioisotope sails behavior was verified, identifying the most suitable one to represent the propulsive system under study: the profile having negative exponential proper acceleration. Finally, the theoretical results of the radioisotope sail’s possible use as a propulsion system for a mission to Pluto were calculated. The sail characteristics are such as to make this system potentially interesting, in comparison with the classic propulsion systems, as the hypothetical flight times toward Pluto are significantly lower. However, the performances are not so high as to justify, at least in this first study, their use for interstellar missions.