Launch: 18 October 1989
Orbital insertion: 8 December 1995
Launch vehicle: Space Shuttle Atlantis
Vehicle mass (orbiter): 2,380kg (5,200lb)
Spacecraft dimensions (orbiter): 5.2m (17ft) high, 11m (32ft) wide
Missions: Galileo orbiter, Galileo probe
Flybys: Earth, Venus, asteroid belt, Io, Europa, Ganymede
Galileo remains the only spacecraft to orbit Jupiter, and its probe was the first to enter the Jovian atmosphere. It gave us numerous insights into Jupiter and its moons. Highlights from the mission included mapping the structure and extent of the Jovian magnetosphere, observing ammonia clouds in Jupiter’s atmosphere and discovering that Jupiter’s ring system is formed by dust created when asteroids smash into the small inner moons. Galileo also found evidence of liquid oceans under the surfaces of Callisto, Europa and Ganymede, while finding thin atmospheric layers on the same moons.
Its later discoveries include a magnetic field on Ganymede, plus evidence of strong volcanic activity on Io and interactions between plasma in Io’s atmosphere and Jupiter’s atmosphere. Galileo had the first spacecraft encounter with an asteroid (951 Gaspra) and performed the first experiments in astrobiological remote sensing.
The craft was damaged by its long contact with Jupiter’s intense radiation and was deliberately crashed into Jupiter’s atmosphere in 2003, to avoid potentially contaminating the Jovian moons with bacteria from the planet.