The National Aeronautics and Space Administration (NASA) has announced that the Cassini spacecraft is now nearing its "retirement" after 20 years of service.

As part of the so-called "grand finale," Cassini will orbit a previously unexplored region between Saturn and its rings 22 times. The spacecraft has already completed 20 ring dives since the beginning of its suicidal plunge in November 2016.

NASA estimates that Cassini will enter Saturn's atmosphere on Sept. 15, 2017. Cassini will continue to send data as it plunges to Saturn before burning up and crashing into the planet's surface.

"Cassini will make some of its most extraordinary observations at the end of its long life," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory, in a press release. "Cassini's grand finale is so much more than a final plunge. It's a thrilling final chapter for our intrepid spacecraft, and so scientifically rich that it was the clear and obvious choice for how to end the mission."

On April 22, Cassini will once again use Titan's gravity to alter its flight path, shrinking its orbit so that it could pass between Saturn and the inner edges of its rings. Astronomers predict that the gap between Saturn and its rings will be clear of large particles that can potentially damage the spacecraft.

As an additional safety precaution, NASA plans to use Cassini's large antennae as a shield to determine if the environment is safe enough for scientific instruments.

The Cassini spacecraft was launched into space on Oct. 15, 1997 from Cape Canaveral Air Force Station in Florida. Since reaching Saturn's system on June 30, 2004, the Cassini spacecraft has been sending valuable data and images of Saturn and its moons.

Some of the most notable discoveries using data from the Cassini spacecraft include the liquid methane sea on Saturn's moon Titan and a global ocean showing indications of hydrothermal activity within the icy moon Enceladus.