was launched on October 18, 1989. It has used planetary gravity to put
itself on a trajectory to Jupiter. This technique allows Galileo to
change velocity as it passes close by a planet. During Galileo's six-year
path to Jupiter it has traveled past Venus once and Earth twice, with two
passes through the asteroid belt that provided flybys of Gaspra and Ida.
of 2 main parts: an orbiter and an atmospheric probe. The Atmospheric
Probe is inside the Orbiter. The probe was released from the orbiter 148
days before it came to Jupiter and entered Jupiter's atmosphere to study
the temperature, pressure and composition of the cloud layers and send its
data back to the orbiter. The Galileo probe arrived at Jupiter on December
7, 1995. Preliminary details about what the Probe discovered is available
from the Galileo Probe home pages.
Complete with the
probe mission, the Galileo is in orbit about Jupiter. During its two year
orbital mission, close flybys are planned of the Galilean satellites
Europa, Ganymede, and Callisto (one each on ten of eleven orbits). Io,
another Galilean moon, was scheduled to be visited with a close flyby just
prior to the probe entry into Jupiter; however, this activity was
cancelled due to a tape recorder problem . Galileo will also study
Jupiter's atmosphere and magnetosphere during each of its orbits around
of temperature, pressure and composition of cloud layers, and
atmosphere and magnetosphere.