On Asteroid Retrieval Missions Enabled by Invariant Manifold Dynamics

In recent years, the retrieval of entire asteroids has received significant attention, with many approaches leveraging the invariant manifolds of the Circular-Restricted Three-body Problem to capture an asteroid into a periodic orbit about the $L_1$ or $L_2$ points of the Sun-Earth system. Previous works defined an `Easily Retrievable Object' (ERO) as any Near-Earth Object (NEO) which is retrievable using these invariant manifolds with an impulsive $\Delta v$ of less than $500$ m/s. We extend the previous literature by analysing the Pareto fronts for the EROs discovered for the first time, using high-performance computing to lift optimisation constraints used in previous literature, and modifying the method used to filter unsuitable NEOs from the NEO catalogue. In doing so, we can demonstrate that EROs have approximately the same transfer cost for almost any possible transfer time, including single-impulse transfers, which could offer significant flexibility to mission designers. We also identify $44$ EROs, of which $27$ are new, and improve on previously-known transfer solutions by up to $443$ m/s, including $17$ new capture trajectories with $\Delta v$ costs of less than $100$ m/s.