Free-Space optical communication is expected to revolutionize the deep-space communication by providing the high
bandwidth data support for future solar and planetary exploration missions. Due to the cost and up-gradation constraints,
an earth-based receiver seems to be a viable option. A large telescope acting as an optical antenna is required at the
receiver end to support the reasonable data rates (at least in 10s of Mbps range). An array of smaller telescopes
connected to fabricate a larger photon-collecting aperture is an attractive architecture. In this research, performance
analyses of different array architectures are evaluated for a deep-space interplanetary optical communication link
between Mars and Earth with an objective to find a lower bound on the number and sizes of individual telescopes in the
array receiver. The achievable data rates are calculated for opposition and conjunction phases of Mars-Earth orbit.
Various deleterious factors, such as background noise and atmospheric turbulence are also modeled in the simulations.
Total aperture size of various array architectures are kept at 10 m. The comparison of results for different array
architectures show that the performance of a receiver employing an array comprising of 135 telescopes with 0.86 m
aperture diameter each is almost equivalent to a single telescope with 10 m aperture diameter. Further, if the diameter is
reduced below this limit, the performance degradation is substantial.