A systems-level analysis of a high data rate Mars to Earth optical communications link is presented. A feasibility of a minimum 10 Mb/s optical link with the possibility of achieving > 100 Mb/s under certain conditions will be shown. The link design employs a Pulse Position Modulated (PPM) 1.06 μm Mars transmitter with a photon-counting Earth receiver. This study will characterize system performance (link data rate) as a function of orbital position including the complex diurnal and annual variations in the Mars-Earth system. Key system impairments that vary diurnally/annually include loss and turbulence due to the Earth's atmosphere, daytime/nighttime sky background noise, background noise from Mars itself, and space loss due to the relative planetary distances. In addition, transmitter/receiver design parameters and their impact on system performance are discussed.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.