NASA has doomed its $3.26 billion Saturn probe - here's what Cassini may discover on its death spiral

The nuclear-powered robot called Cassini has orbited Saturn for nearly 13 years but has run dangerously low on fuel. NASA doesn't want to risk crashing Cassini into any of Saturn's icy moons, since it could contaminate their hidden oceans. So the space agency just kicked off a death spiral that will send the spacecraft straight into Saturn.

On April 22, Cassini paid a final visit to Saturn's largest moon, Titan, which set the robot on a path to make an unprecedented dive between the Saturn and its innermost rings on April 26.

The new orbit will lead Cassini to a spectacular death on September 15, 2017.

"This is a roller-coaster ride," Earl Maize, an engineer at NASA's Jet Propulsion Laboratory who manages the Cassini mission, said during a press briefing on April 4. "We're going in, and we are not coming out. It's a one-way trip."

In the intervening months, however, the robot will go where none has gone before it, and beam back a treasure trove of photos and data that researchers have thus far only dreamed about.

"It's Cassini's blaze of glory," Linda Spilker, a Cassini project scientist and a planetary scientist at NASA's Jet Propulsion Laboratory, told Business Insider. "It will be doing science until the very last second."

Spilker walked us through what Cassini may see and discover during its final moments.