  A global quantum repeater network involving satellite-based links is likely
to have advantages over fiber-based networks in terms of long-distance
communication, since the photon losses in free space scale only polynomially
with the distance -- compared to the exponential losses in optical fibers. To
simulate the performance of such networks, we have introduced a scheme of
large-scale event-based Monte Carlo simulation of quantum repeaters with
multiple memories that can faithfully represent loss and imperfections in these
memories. In this work, we identify the quantum key distribution rates
achievable in various satellite and ground station geometries for feasible
experimental parameters. The power and flexibility of the simulation toolbox
allows us to explore various strategies and parameters, some of which only
arise in these more complex, multi-satellite repeater scenarios. As a primary
result, we conclude that key rates in the kHz range are reasonably attainable
for intercontinental quantum communication with three satellites, only one of
which carries a quantum memory.
