  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.
