Solar electric propulsion by a solar power sail for small spacecraft missions to the outer solar system

Abstract

Outer solar system exploration by a small spacecraft using a solar power sail is investigated. A solar power sail is an extended form of a solar sail that has thin-film solar cells attached over its surface. This concept makes it possible to generate a large amount of power with less weight resources than conventional means. Thereby, even a small spacecraft, which has a strong constraint on available resources, can drive high-power ion thrusters to obtain large ΔV. Combining electric propulsion with gravity assists allows the spacecraft to reach the outer solar system using less propellant. The spacecraft can not only survive by means of solar power in the outer solar system, but also drive electric thrusters there to perform challenging missions such as asteroid or comet rendezvous. In this paper, a framework for exploring the outer solar system using a 50-kg-class small spacecraft is presented. The characteristics of solar electric propulsion under the solar power sail model are disclosed, and a design scheme for missions to the outer planets and beyond are addressed. Providing the specific design of the 50-kg-class solar power sail-craft, Centaur rendezvous mission design is performed as a feasibility study.