ECE 6390 Satellite communications and Navigation
Course design project

Neptune Deep Space Mission :
Satellite communications system

Table of contents

*      Project Overview

*      System Overview

*      Communications System

*      Orbital mechanics

*      References


Project Overview


Due to their extreme distances from earth, we have sent relatively few probes to the outer gas giants of our solar system (Jupiter, Saturn, Uranus, and Neptune). NASA is proposing an ambitious mission to Neptune within 10 years that will insert 3 probes into the atmosphere, at latitudes of 0, +45, and 45. Due to the size and density of the atmosphere, the probes will take 50 hours to descend to a pressure of 1000 bar. During this time, the probes' scientific instruments will be measuring and recording data and sending it back to earth (presumably through a relay satellite) at a rate of 8 kbps each.


Design Goal


You have been contracted to design the satellite system that collects probe data and sends it real-time back to the earth. Not only is Neptune extremely distant from the earth, but the probes must report back through miles and miles of the planet's dense, exotic atmosphere of hydrogen, helium, and methane. You may assume that earth stations in NASA's Deep Space Network (DSN) ( are available for you to transmit and receive data. Each DSN site contains a 34m diameter dish antenna with Tsys = 20K and aperture efficiency of 0.94. The DSN transmitters are capable of transmitting up to 500,000 watts and at least one station is always visible to Neptune.


How to navigate on this site


I am far from being a good web developer (in fact this is the first site I ever did in my life), but I tried to create links as much as possible so that the reader can find himself/herself throughout the project. The recommended sequence of reading is System Overview, Communications System, and Orbital mechanics. However, the last two are closely related and you will find that you will be going back and forth to understand why certain decisions have been made.