Page 56 - Curriculum Visions Dynamic Book

These space probes took far better pictures of the gas planets, and especially Jupiter and its moons, than had previously been possible.
The success of the Voyager missions encouraged further explorations, and so the Galileo mission was developed. It was no longer possible to use Jupiter as
a slingshot, so a three-times orbit around the Sun was used instead, using first Venus and the Earth as gravity assist planets to increase the orbit and speed until the probe could finally be sent to its destination of Jupiter. It was Galileo that orbited Jupiter for 2 years and dropped a probe into the Jovian atmosphere. Cassini, the most recent of the solar system explorers, also used the same gravity-assist trajectory for its launch toward Saturn.
Voyager
Voyager 1, launched on September 5, 1977, flew by Jupiter in March 1979 and reached Saturn in November 1980. Voyager 2, launched on August 20, 1977, moved more slowly, reaching Uranus on January 2, 1986, and Neptune on August 2, 1989.
The launch vehicle for Voyager 1 was a Titan/Centaur. The first stage Titan was powered by both solid and liquid fuel engines. The Centaur stage, 20 metres long and 3 metres in diametre, burned
a fuel combination of liquid hydrogen and liquid oxygen. The Titan boosted the Voyager-Centaur combination into low Earth orbit, and the Centaur plus a small solid fuel rocket provided the energy for Voyager 1 to escape Earth orbit.
 The flight paths of the two Voyager spacecraft. Launch from Earth August–September 1977
Voyager 2
Voyager 2 passes Neptune August 1989
Neptune
Jupiter
Voyager 1 passes Saturn November 1980
Sun
Voyager 2 passes Saturn August 1981
 The principle of a slingshoT TrajecTory seen in plan.
slingshot trajectory A path chosen to use the attractive force of gravity to increase the speed of a spacecraft.
Orbit of Jupiter
Sun
Orbit of Earth
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Uranus
Probe sent on initial orbit of Jupiter
The orbit is deflected and accelerated by the gravitational force of Jupiter, and the probe heads on a new course orbiting Jupiter and heading for Saturn.
Voyager 1
Orbit of Saturn