  Interstellar probes can carry out slingshot manoeuvres around the stars they
visit, gaining a boost in velocity by extracting energy from the star's motion
around the Galactic Centre. These maneouvres carry little to no extra energy
cost, and in previous work it has been shown that a single Voyager-like probe
exploring the galaxy does so 100 times faster when carrying out these
slingshots than when navigating purely by powered flight (Forgan et al. 2012).
We expand on these results by repeating the experiment with self-replicating
probes. The probes explore a box of stars representative of the local Solar
neighbourhood, to investigate how self-replication affects exploration
timescales when compared with a single non-replicating probe.
  We explore three different scenarios of probe behaviour: i) standard powered
flight to the nearest unvisited star (no slingshot techniques used), ii) flight
to the nearest unvisited star using slingshot techniques, and iii) flight to
the next unvisited star that will give the maximum velocity boost under a
slingshot trajectory.
  In all three scenarios we find that as expected, using self-replicating
probes greatly reduces the exploration time, by up to three orders of magnitude
for scenario i) and iii) and two orders of magnitude for ii). The second case
(i.e. nearest-star slingshots) remains the most time effective way to explore a
population of stars. As the decision-making algorithms for the fleet are
simple, unanticipated "race conditions" amongst probes are set up, causing the
exploration time of the final stars to become much longer than necessary. From
the scaling of the probes' performance with star number, we conclude that a
fleet of self-replicating probes can indeed explore the Galaxy in a
sufficiently short time to warrant the existence of the Fermi Paradox.
