Once it has completed several more swings through Saturn’s complete system of rings, the craft will be sent spiralling into the planet’s atmosphere, where it will be destroyed. And its date with death has already been picked – 15 September later this year.

It will be the conclusion of one of the most successful planetary missions ever undertaken. As Carolyn Porco, the head of Cassini’s imaging team, put it: “We’ve lived a bold and daring adventure around the solar system’s most magnificent planet.”

Cassini was launched in 1997 and took seven years to reach Saturn, which – with its large family of moons – orbits the sun more than a billion kilometres from Earth. In early 2005, the spacecraft released a small European-built probe, Huygens, which landed successfully on Saturn’s huge moon Titan, a world with a dense atmosphere, and which is the only object in space other than Earth where there is clear evidence of bodies of surface liquid. Huygens revealed these to be made up of lakes of liquid ethane and methane, while sensors on the lander indicated that Titan had a crunchy surface with a texture like crème brûlée, according to one researcher.

It shot through the gap and came out in excellent shape. No spacecraft has ever been this close to Saturn before

Since then, observations by Cassini of Titan have indicated that the planet may also have a subsurface ocean, made mostly of water, and that this could provide a home for alien life. Titan’s hot core is probably keeping that underground ocean in a warm liquid state, while ethane, methane and other hydrocarbons on the surface could be filtering down through Titan’s crust into this hidden sea, creating a perfect incubator in which primitive life forms could evolve.