A global exploration method to identify families of cycling Earth–Mars trajectories

Abstract

Cycler mission architectures consider the use of a large space vehicle that cycles continuously between Earth and Mars, describing a near-ballistic path that includes flybys at the two planets. While this large spacecraft can be equipped with the life support system appropriate for a long interplanetary flight with a crew, taxi vehicles of reduced size are sufficient to ensure the connection between the interplanetary vehicle and each planet. This study employs the relations of Keplerian motion and proposes a global exploration methodology capable of identifying the entire set of cycling paths belonging to two distinct families, without any need of solving the Lambert’s problem. This result is achieved by reducing the problem to the solution of a single nonlinear equation with only an unknown quantity, constrained to a proper interval, directly related to feasibility of the cycler. Some well-known solutions are found as special cases, together with further remarkable cycling trajectories, which often exhibit very interesting features, i.e. limited time of flight or reduced hyperbolic velocities.