An unmanned NASA spacecraft sent to study the planet Jupiter & its moons. Launched Oct. 18, 1989 by the Space Shuttle Atlantis. Arrived at Jupiter on Dec. 7, 1995, via gravitational assist flybys of Venus & Earth. Conducted the first asteroid flyby, discovered the first asteroid moon, & launched the first probe into Jupiter's atmosphere. On Sept. 21, 2003, after 14 years in space, Galileo's mission was terminated by sending it into Jupiter's atmosphere at a speed of nearly 50 kps to avoid contaminating local moons with bacteria from Earth.