Galileo Satellite Tour: Orbit Determination Performance

The Galileo mission is an ambitious attempt to explore the Jovian system by spacecraft. This voyage of exploration is a logical successor to the reconnaissance voyages of Pioneers 10 and 11, Voyagers 1 and 2, and Ulysses. These spacecraft merely flew past Jupiter, spending relatively little time in its system. Galileo differs from these earlier spacecraft in that it will remain within the Jovian system, studying the planet and its four major satellites for a period of two years. Insertion into orbit around Jupiter will occur on December 7, 1995. The portion of the mission encompassing observations of Jupiter and the major and minor satellites, and magnetospheric mapping, has become known as the Jovian tour. During this period Galileo will encounter each of Europa, Ganymede, and Callisto at least three times on trajectories that will bring it to altitudes from 200 to 3100 kilometers.