NASA's Cassini spacecraft carrying ESA's Huygens probe was launched on October 15, 1997, and is arguably the most successful space exploration mission ever. In just under three days from now, it will complete its decades- long mission by entering the atmosphere of Saturn and disintegrating, completing what NASA is calling "The Grand Finale." NASA describes the journey:
Beginning in 2010, Cassini began a seven-year mission extension in which it completed many moon flybys while observing seasonal changes on Saturn and Titan. The plan for this phase of the mission was to expend all of the spacecraft's propellant while exploring Saturn, ending with a plunge into the planet's atmosphere. In April 2017, Cassini was placed on an impact course that unfolded over five months of daring dives—a series of 22 orbits that each pass between the planet and its rings. Called the Grand Finale, this final phase of the mission has brought unparalleled observations of the planet and its rings from closer than ever before.
On Sept. 15, 2017, the spacecraft will make its final approach to the giant planet Saturn. But this encounter will be like no other. This time, Cassini will dive into the planet's atmosphere, sending science data for as long as its small thrusters can keep the spacecraft's antenna pointed at Earth. Soon after, Cassini will burn up and disintegrate like a meteor.
To its very end, Cassini is a mission of thrilling exploration. Launched on Oct. 15, 1997, the mission entered orbit around Saturn on June 30, 2004 (PDT), carrying the European Huygens probe. After its four-year prime mission, Cassini's tour was extended twice. Its key discoveries have included the global ocean with indications of hydrothermal activity within Enceladus, and liquid methane seas on Titan.
And although the spacecraft may be gone after the finale, its enormous collection of data about Saturn—the giant planet itself, its magnetosphere, rings and moons—will continue to yield new discoveries for decades.It took Cassini 7 years to arrive at Saturn, where it then spent more than a decade touring the ringed planet and its intriguing moons.
Why does Cassini matter so much? Here are 9 ways. It's enough to make one proud to be of the human species, and of the belief we can do "big things." It's an achievement to be applauded and emulated.
Here's a video depiction from NASA on Cassini and its "Grand Finale:"