As the saying goes all good things must come to an end and the same will go for the Cassini mission to Saturn as it begins its final year of operation.
Dubbed the Grand Finale, the space agency will carry out Cassini’s final observations into two phases.
Phase one begins on November 30, 2016 when the spacecraft’s orbit will send it just past the outer edge of Saturn’s main rings.
In a series of 20 weekly orbits, Cassini will come within 7,800 kilometers of the center of Saturn’s narrow and peculiar F-ring.
“During the F-ring orbits we expect to see the rings, along with the small moons and other structures embedded in them, as never before,” said Cassini project scientist Linda Spilker at JPL in a press release.
Sometime in April 2017, Cassini will kick off the second phase.
The orbiter will fly close to Saturn’s biggest moon Titan, which will alter Cassini’s orbit so it can fly through the roughly 2,400 kilometer wide gap between the planet and its rings.
Beginning on April 27, 2017, Cassini will be begin to make a series of 22 dives through this so-far unexplored gap.
NASA says that this Grand Finale will allow Cassini to make the closest-ever observations of Saturn, take some ultra-close images of its atmosphere, directly analyze dust-sized particles in its main rings, and sample the outer limits of its atmosphere.
The space agency says it hopes the final months and days of Cassini’s mission will provide scientists with information and insight about Saturn’s interior structure, the exact length of a Saturn day, and the total mass of the rings, something that could finally determine their age.
“It’s like getting a whole new mission,” said Spilker. “The scientific value of the F-ring and Grand Finale orbits is so compelling that you could imagine a whole mission to Saturn designed around what we’re about to do.”
The mission to Saturn began on October 15, 1997 when the unmanned Cassini-Huygens spacecraft, atop a Titan IVB/Centaur rocket, was launched from Cape Canaveral, Florida.
After a nearly seven year voyage, Cassini-Huygens entered orbit around the giant ringed planet on July 1, 2004.
The mission has been a combination of efforts between NASA, the European Space Agency and the Italian Space Agency and a total of seventeen nations.
The orbiter/lander combination circled Saturn together for just over five months.
Then on December 24, 2004 the Huygens lander was detached from the orbiter, allowing it to land on Saturn’s moon Titan on January 14, 2005.
As the lander headed through the moon’s thick nitrogen-rich atmosphere to its surface, Cassini continued its orbit around the planet.
According to NASA, the Huygens lander showed Titan to be a lot like early Earth before life began to emerge and evolve. The moon had methane rain, showed signs of erosion and drainage channels, as well as dry lake beds. In its atmosphere was a mix of complex hydrocarbons, including benzene.
Over the last twelve years the Cassini orbiter has provided scientists with numerous unique insights and close-up views of Saturn, as well as its rings and moons.
With Cassini, scientists were able to discover and study plumes of icy water that periodically blasts from Saturn’s moon Enceladus. The orbiter made it possible to observe changes in Saturn’s famous rings and possibly the birth of a new moon.
Going out with a bang
The orbiter’s mission will come to a dramatic conclusion on Sept. 15, 2017 when it will be sent diving through Saturn’s atmosphere toward the planet itself.
As Cassini makes its final plunge the space agency says that the intrepid spacecraft will continue to gather and send back data about Saturn’s chemical composition until its signal is finally lost.
NASA says friction with the atmosphere will build during its descent and will cause the spacecraft to burn up like a meteor soon after signal loss.