NASA's Cassini ready for final plunge toward Saturn

CAPE CANAVERAL, Fla (KABC) -- NASA calls its Cassini spacecraft "the ultimate teacher ready for retirement."

After circling Saturn for 13 years collecting valuable data, mission control at NASA's Jet Propulsion Laboratory in Pasadena will direct Cassini to dive toward the planet on Friday at 5 a.m. PST for one final mission before it is expected to burn up and break apart.

"We get the maximum amount of science to the very, very end," said NASA Associate Administrator Thomas Zurbuchen.

Thanks to Cassini, launched in 1997, scientists have learned about Saturn's atmosphere, weather and magnificent rings. Cassini also discovered dozens of moons near Saturn, including Titan and Enceladus, which is believed to have a liquid ocean located under its surface.

"By finding those other ocean worlds out there at Saturn, where we did not expect they would exist, it's really changed the paradigm that we think about how often we might find habitable environments," said Curt Nieber, a Cassini program scientist at NASA.

When Cassini plunges to its death on Friday, scientists are hoping the spacecraft will continue gathering data that will answer several more burning questions, including: How long is one day on Saturn? And, how old are those famous rings?

There's also another reason for letting Cassini burn. NASA admits the spacecraft was not extremely clean when it launched 20 years ago.

"Earth microbes are very hearty, and there are some microbes out there that can hitch a ride on a spacecraft," said Nieber. "(Microbes) can survive years, a decade or two, in space, in the vacuum of space, and then once you reintroduce them to a nice, watery warm environment with food in it, they come back to life."

Nieber said he is sad to see Cassini go, but he's excited about launching newer, more sophisticated technology and exploring Saturn further.