In order to reach Jupiter, Galileo needed more power than just what it could carry. It had to use the gravitational pull of certain other planets to slingshot it to Jupiter. First, Galileo used the gravitational fields of Venus and Earth to pick up enough velocity to get to Jupiter. This 38-month Venus-Earth-Earth Gravity Assist phase ended with the second Earth flyby on December 8, 1992. During this initial time, Galileo took every opportunity to make scientific observations and test the spacecraft's scientific capabilities.

As Galileo flew deeper into space, it flew by some extremely unique and rare sights. In late July 1994 Galileo was the only observer in a position to obtain images of the far side of Jupiter when more than 20 fragments of Comet Shoemaker-Levy plunged into the night-side atmosphere over a six-day period.