Redmond company's thrusters helped Cassini plunge into Saturn

REDMOND, Wash. -- The world -- and the Solar System -- said goodbye to an important piece of science Friday.

The Cassini-Huygens Spacecraft plummeted into Saturn, the second-largest planet in the Solar System. The planned plunge brought the spacecraft's 20-year mission to an end.

Confirmation of Cassini's expected demise came about 7:55 a.m. EDT. That's when radio signals from the spacecraft — its last scientific gifts to Earth — came to an abrupt halt. The radio waves went flat, and the spacecraft fell silent.

Cassini actually burned up like a meteor 83 minutes earlier as it dove through Saturn's atmosphere, becoming one with the giant gas planet it set out in 1997 to explore. But it took that long for the news to reach Earth a billion miles away.

The only spacecraft to ever orbit Saturn, Cassini showed us the planet, its rings and moons up close in all their splendor. Perhaps most tantalizing, ocean worlds were unveiled on the moons Enceladus and Titan, which could possibly harbor life.

Dutiful to the end, the Cassini snapped its last photos Thursday and sampled Saturn's atmosphere Friday morning as it made its final plunge.

Propulsion systems on the mission were designed by Redmond based company Aerojet RocketDyne.

From the launch of the  spacecraft with the Titan IV launch vehicle, to the final propulsion system used to push into Saturn, Aerojet had a hand, says Cassini Project Engineer Olwen Morgan.

"Cassini has two complete complete propulsion systems," Morgan said.

On Friday, as Cassini entered Saturn's atmosphere, Aerojet Rocketdyne's Reaction Control Thrusters worked to counter atmospheric torques, helping Cassini fight to keep its high gain antenna pointed at Earth to relay its final mission.

It's not particularly sad to see Cassini crash into Saturn, Morgan says.

'It's for the protections of Saturn's moons," Morgan said. "We didn't want to accidentally inoculate them with microbes from Earth if there was a possibility of some kind of life on the moon."

In fact, NASA will be getting so much data, the mission can hardly be considered complete.

"They will be reducing the data from that mission for years to come," Morgan said. "So the mission's not over."

Aerojet RoctDyne has had a hand in many other propulsion systems, including on the Voyager Missions, the New Horizons Mission and Mars rover missions.