A near term pole-sitter using hybrid solar sail propulsion

In this paper we investigate optimal pole-sitter orbits using hybrid solar sail and solar electric propulsion(SEP). A pole-sitter is a spacecraft that is constantly above one of the Earth's poles. Optimal orbits, that minimize propellant mass consumption, are designed using a shape-based first guess followed by an optimal control problem solved with a direct method. SEP and hybrid spacecraft are compared in terms of payload mass fraction and mission lifetime, investigating the conditions under which the hybrid sail allows saving on the spacecraft initial mass. It is proposed that a hybrid solar sail and SEP system may be a means of enabling challenging long-duration, high energy missions by using a modest solar sail to enhance the performance of existing SEP technology.