NASA's Cassini spacecraft begins final approach to Saturn: See pics

Cassini launched into space on October 15, 1997 on an exploration mission and after a seven-year journey to the ringed planet, entered obit around Saturn in 2004.

Three other spacecraft have flown by Saturn - Pioneer 11 in 1979, followed by Voyager 1 and 2 in the 1980s.

Confirmation of Cassini's expected demise came about 7:55 a.m. EDT.

Project manager Earl Maize said: "Congratulations to you all. Tomorrow, our spacecraft will be part of the planet it studied for so long", Cassini's team said on Twitter Thursday night. "The mood of the team heading toward end of mission is a mix of joy and satisfaction, given the mission's enormous success, tinged with sadness at the impending loss of their stalwart spacecraft".

The first probe to spend any kind of time at Saturn, Cassini - a joint effort of NASA, the European Space Agency and the Italian Space Agency (hence it being named after an Italian astronomer) - has long outlived its planned four-year mission.

The final stream of data from Cassini was received at NASA's Jet Propulsion Laboratory (JPL) in southern California.

"I have been working on Cassini for nearly 30 years, so it has been a major part of my career, and certainly a highlight", he says. "This is a celebration of an fantastic mission and incredible legacy".

The space mission is regarded as one of the most ambitious and successful ever undertaken. "It's just very heartening".

Including Titan, Cassini explored a total of 19 Saturnian moons in detail. It's not [just for] scientists in the ivory tower; it's for humanity.

Cassini is set to make groundbreaking scientific observations of Saturn.

A final close flyby of the moon Titan on April 22 used the moon's gravity to reshape Cassini's trajectory so that the spacecraft leapt over the planet's icy rings to pass between the rings and Saturn.

Cassini's imaging camera will take a last look at the Saturn system on the day before the plunge and will be off during this final descent.

As Cassini hurtles on towards its death, the program head at NASA - Curt Niebur - is philosophical about the probe's final fate.

The probe, which was about 9 feet wide and weighed about 700 pounds, was plunged into Saturn's giant moon Titan in 2005.

Cassini also found a global ocean on the moon Enceladus, with ice plumes spouting from its surface. Further study of the geysers has since indicated that Enceladus' subsurface water ocean might have conditions suitable for life.

Huygens and Cassini found Titan to have "rivers" and "seas" of liquid hydrocarbons, in a landscape remarkably Earth-like in appearance.

"We hope to get a measurement of the core mass, how many heavy elements are concentrated in the interior of Saturn", said Iess. "I could not ask for more".

These days, when one is discussing space missions beyond the immediate vicinity of Earth and the moon, the most-frequently brought up topic is the many plans to go to Mars.

  • Carolyn Briggs