The National Aeronautics and Space Administration on Tuesday said its Cassini spacecraft, which began its orbit around Saturn in 2004, will undertake its final mission with a series of dives between Saturn and its rings starting April 26. The spacecraft has relayed data about a global ocean that showed “indications of hydrothermal activity within the icy moon Enceladus and liquid methane seas on the planet’s moon Titan”, a statement said.

“No spacecraft has ever gone through the unique region that we will attempt to boldly cross 22 times. What we learn from Cassini’s daring final orbits will further our understanding of how giant planets, and planetary systems everywhere, form and evolve. This is truly discovery in action to the very end,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at Nasa Headquarters in Washington.

With the spacecraft low on fuel after its launch 20 years ago, Nasa said it was time to end the mission. The planet is expected to complete its plunge by September 15, when it will send its final data report, the statement said. “Cassini will make some of its most extraordinary observations at the end of its long life,” said Linda Spilker, Cassini project scientist.

The team hopes to learn more about the planet’s internal structure and the origins of the rings as well as obtain the “first-ever sampling of Saturn’s atmosphere and particles coming from the main rings” and get documentation of the planet’s clouds and inner rings.

The team is scheduling the commands for the craft to conduct its observations, called a sequence. Nasa posted a link to an animated video about Cassini’s Grand Finale.

The Cassini-Huygens mission is a collaborative effort of NASA, European Space Agency and the Italian Space Agency.