A Boeing Inertial Upper Stage (IUS) booster rocket (white and gold at bottom of photo), mated to Galileo space probe, is shown moments before being deployed into space from the cargo bay of the NASA space shuttle Atlantis on Oct. 18, 1989. The Earth is in the background. Deployment came about six hours after launch from Kennedy Space Center in Florida. The IUS aimed Galileo and fired its two solid rocket motors in sequence to give the probe enough energy to escape Earth's gravitational pull. Galileo journeyed across the solar system to study Jupiter and its moons.