NAVIGATION ANALYSIS FOR EROS RENDEZVOUS AND ORBITAL PHASES

The navigation of the Near Earth Asteroid Rendezvous (NEAR) mission is described. This mission is the first of several low cost missions bei ng planned to study the solar system. The primary purpose of this miss ion is to orbit the near-Earth asteroid 433 Eros and study it at close range. Elements of the NEAR Navigation System are described including navigation instrumentation, the spacecraft attitude control and propu lsion system and the ground system consisting of tracking stations and software. Navigation accuracies are given for spacecraft orbit predic tion and control. Key navigation parameters are noted, including the p hysical parameters that describe Eros such as mass, moments of inertia , and gravity harmonics. We also describe the orbit determination in s upport of science observations while in orbit about Eros.