The Cassini spacecraft is about to begin its great cosmic swan dive.

On Saturday morning, the spacecraft, which has been circling Saturn and its environs for the last 13 years, will skim over the hazes of Titan, the ringed planet’s biggest moon. Like a heavy hand, Titan’s gravity will reach out and pull Cassini onto a new path, downward into the narrow gap between Saturn and its innermost ring, where no human artifact has ever gone.

Cassini will penetrate that formerly inviolate space not once but 22 times, about once a week until Sept. 15, when it will crash into Saturn and be incinerated. This summer then is the last hurrah of sorts for Cassini and the team that has guided it all these years.

Two years ago, Carolyn Porco, the longtime leader of Cassini’s imaging team, teared up during an on-camera interview about the mission, an example of what humans working together could do. “It was glorious, just glorious,” she said.

She and many of her colleagues cut their teeth on the Voyager missions, which toured the worlds of the outer solar system during the 1980s and ’90s and are still out there dancing on the magnetic winds that guard the passage to interplanetary space. It was a generation steeped in “Star Trek,” “2001: A Space Odyssey” and optimism. Dr. Porco even labeled her online reports a captain’s log.