Project Requirements

The goal of the project is to successfully design a working communications link for a deep-penetration Neptune probe mission that NASA is planning within 10 years. Three probes will be inserted into the dense Neptunian atmosphere at latitudes of -45º, 0º, and 45º. During their short 50 hour lifetime, the probes will descend 420 kilometers into the atmosphere (only 1.6% of the total atmosphere!), collect data during this descent and somehow send this data back to the Earth. Each probe has a compressed data rate of 8 kilobits per second (kbps), so the total data rate going to the Earth is 24 kbps.

All aspects of the design will be considered; the trajectory of the probes as they fall into the Neptunian atmosphere, the orbit of the relay satellite around Neptune, and the positioning of the dish antenna on the satellite to maintain a communications link with the Earth.

A NASA project, the mission will have access to NASA's Deep Space Network (DSN), a collection of large dish antennas around the world that are used to communicate with interplanetary spacecraft. These massive antennas have a diameter of 34 meters and are capable of transmitting up to 500,000 Watts. The DSN antennas are strategically placed such that at least one antenna is always in line of sight of Neptune.

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References:
1. ECE6390 Home Page (http://www.propagation.gatech.edu/ECE6390), Dr. Greg Durgin