The spacecraft is set to fly close to the giant moon Titan - an encounter that will bend its trajectory just enough to send it into the atmosphere of the ringed planet on Friday.
Ever since it arrived at Saturn 13 years ago, the probe has used the gravity of Titan - the second biggest moon in the Solar System - to slingshot itself into different positions from which to study the planet and its stunning rings.
It has been a smart strategy because Cassini would otherwise have had to fire up its propulsion system and drain its fuel reserves every time it wanted to make a big change in direction.
As the probe passes Titan, it will take one last set of images of this extraordinary world where orange skies produce liquid methane rains that run into huge seas, and where the vast dunes on the moon's surface are made from a plastic-like sand.
In the final three hours or so before impact on Friday all data acquired by the spacecraft will be relayed straight to Earth, bypassing the onboard solid state memory.
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