‘Our Saturn years’

The Cassini satellite has almost run out of fuel.

Its final mission, on 15 September, is to dive into the planet’s thick atmosphere, where it will meet a fiery end.

An encounter with the moon Titan has nudged Cassini’s trajectory on to a collision course with Saturn. Nasa has called this manoeuvre a “goodbye kiss”.

For 13 years, the orbiter has been sending back to Earth images of its extraordinary discoveries at Saturn.

It has documented the possible birth of a moon, tasted an extra-terrestrial ocean and watched as a giant storm encircled the entire planet.

Linda Spilker will be there to wave it off.

“For me, when I first started working on Cassini in 1988, my oldest daughter Jennifer had just started kindergarten. And now, here we are in 2017, she’s married and she has a daughter of her own,” says Dr Spilker, project scientist for the Cassini mission.

Computer animation - known as the “ball of yarn” - showing all of Cassini's orbits of Saturn(Nasa)

Computer animation – known as the “ball of yarn” – showing all of Cassini’s orbits of Saturn

The mission set off from Earth in 1997 to explore the giant ringworld and its menagerie of moons.

After joining the Jet Propulsion Laboratory (JPL) in 1977, Dr Spilker worked on the Voyager missions to the outer Solar System.

She describes herself as a “Voyager mom”.

“My two children were born, very strategically, in a window on Voyager between the Saturn and Uranus flybys, because there were five years between them.”

Cassini-Huygens in a Nasa test chamber before launch, 1997(Nasa)

Cassini-Huygens in a Nasa test chamber before launch, 1997

With Cassini proceeding apace, Dr Spilker’s attentions were turned to Saturn full-time.

There were originally two spacecraft: Cassini and Huygens, which travelled to Saturn attached to one another.

Cassini is the American orbiter, which has been exploring Saturn since 2004.

Huygens was a European landing probe, released from the Cassini “mothership” shortly after arrival in Saturn’s orbit.

In January 2005, Huygens descended through the atmosphere of the saturnian moon Titan, sending back information about its environment.

A fascination with Saturn’s magnificent rings led Linda Spilker to join Cassini-Huygens when it was still on the drawing board.

She has been with the mission ever since.

Linda Spilker in 1989(Nasa)

Linda Spilker in 1989

But Dr Spilker isn’t the only one – several members of the team have worked on the mission for the best part of a decade or longer.

Their families have been on holiday together and, in some cases, their children have grown up with each other.