In just a few days, the Cassini mission will end by colliding with Saturn and the collision course has now been set thanks to a final flyby of Titan, the ringed giant's largest moon, on September 11.
This final distant encounter has been nicknamed a "goodbye kiss" by mission engineers and was a necessary step for the mission. By flying at an altitude of 119,049 kilometers (73,974 miles) above Titan the spacecraft conducted a “pop-down” maneuver to take it on a lower orbit than it has currently been on.
“Cassini has been in a long-term relationship with Titan, with a new rendezvous nearly every month for more than a decade,” Cassini Project Manager Earl Maize at NASA's Jet Propulsion Laboratory said in a statement. “This final encounter is something of a bittersweet goodbye, but as it has done throughout the mission, Titan's gravity is once again sending Cassini where we need it to go.”
Over its 13-year mission around the system, Cassini has orbited Titan 127 times, including the one when it deployed its companion lander Huygens, which gave us the first surface pictures of the moon. Over the years, it had studied its complex atmosphere, its seasonal changes, and its lakes of liquid methane.
Cassini is now in an orbit that will lead it into the heart of Saturn. The probe will be destroyed to avoid potential contamination of the system from Earth’s microorganisms that may have hitched a ride on the spacecraft. The place that scientists really don’t want to contaminate is Enceladus.
Earlier this year, researchers did confirm that beneath the ice of Enceladus there’s a warm ocean with hydrothermal activity, and to avoid any potential risk of contamination the mission directorate decided to have Cassini face a fiery death and get destroyed in the atmosphere of Saturn.
The analysis of Enceladus was possible by having Cassini flying through its plume. A few weeks ago, the probe took its final video of Enceladus’ plume being ejected from the southern pole of the icy moon.
On Friday, September 15, Cassini will take its swan dive into Saturn, the perfect conclusion for the mission’s Grand Finale. And while no new pictures will be coming from the Saturn’s system for many years, scientists will be busy. Not only is there still so much data to analyze but research teams are already thinking of the next big missions to the planet.