And today, the spacecraft has likely achieved another milestone: Using its 13-foot-wide high-gain antenna as a shield, it probably has made the first ever dive between the rings and the giant gaseous planet itself.
It's a noble end to a long trip.
However, the mission will soon come to a fiery end: The spacecraft is dangerously low on a propellant that's required to correct or change its orbit. Some of the areas had been imaged by Cassini before, but not using radar, according to a Titan-ahead-grand-finale.html" target="_blank">statement from NASA.
But it isn't the navigation that has NASA officials anxious.
From a navigation standpoint, it was "an easy shot", Maize said.
It's treacherous territory. A particle from the rings - even as small as a speck of sand - could cripple Cassini, given its velocity. The latest feed from NASA shows the satellite approaching the ring of Saturn and is breathtakingly handsome. Although Cassini is the one of four spacecrafts to enter Saturn, it was the first to enter orbit.
The odds are in Cassini's favor. "But we are certainly going to provide more excitement".
That may sound pretty safe to you, but NASA really hates risk.
The mission can not be duplicated and it's never been done before.
The Cassini is heading to a place where no ship has gone before.
Saturn houses about more than 60 moons and Cassini has made several new discoveries on some that may have conditions conducive for life. The spacecraft made its 127th and final close approach to Titan last week on April 21 and sent back a lovely new picture of the Earth, as seen from Saturn's rings. However, there are still fundamental questions about Saturn that have yet to be answered. These vary from micron-sized grains (a millimetre is equal to 1,000 microns) to mansion-sized chunks - and they could all collide with the spacecraft.
Assuming all goes to plan, the observations of unexplored regions will offer researchers an opportunity to better understand the planet's interior and the origin of its rings.
The spacecraft will reveal the in-depth secrets of the rings as, "If the rings are massive, this means that they are old". "On the other hand, if they are less massive, perhaps they are very young, forming as little as 100 million years ago". After it dropped off a probe called Huygens in 2004, it began circling the planet and spying on its vast collections of moons and rings.
A new stage of Cassini's mission is complete, starting now to explore the rings of Saturn.
The hexagonal jet streams around the north pole of Saturn. Cassini will also observe the Earth and the Sun during the first deep dive orbit.