Galileo probe. Artist's impression of the Galileo Jupiter spacecraft releasing its atmospheric probe. Galileo is the first mission to the giant planet since the Voyager spacecraft in 1979. The probe, released on 13 July 1995, will encounter Jupiter on 7 December 1995. After hitting the upper atmosphere at 47 kilometres per second, the probe will decelerate rapidly, eventually deploying a parachute. Numerous instruments will take measurements of Jupiter's atmosphere in the 75 minutes before the probe is crushed by the intense pressures of the lower atmosphere. Galileo will meanwhile enter orbit and begin a two-year exploration of the Jupiter system.