NASA's Cassini aircraft on Saturn probe makes first ring-grazing plunge

In order to prepare for its grand finale which is planned for the next year, NASA’s Cassini spacecraft succeeds in making its first close past the edges of Saturn’s rings last Sunday.

The concluding mission phase of the spacecraft began on November 30. The spacecraft crossed the plane of Saturn’s rings on December 4 at the time 5: 09 am PST at a distance of about 91,000 kilometres above the planet’s cloud tops, according to NASA.

This tells the approximate location of a dusty ring which is produced by the small moons of the planet, namely Janus and Epimetheus, and a distance of 11000 kilometers from the centre of Saturn’s F ring.

"Cassini's imaging cameras obtained views of Saturn about two days before crossing through the ring plane, but not near the time of closest approach," NASA said in a statement on Monday.

"The focus of this first close pass was the engine maneuver and observations by Cassini's other science instruments. Future dives past the rings will feature some of the mission's best views of the outer regions of the rings and small, nearby moons," it added.

Just an hour before the spacecraft made the ring-plane crossing, the spacecraft performed a short burn of its main engine. The burn lasted for about six seconds.

After 30 minute of the approach to ring plane, Cassini closed its canopy-like engine cover as a protective measure.

As few hours were passed  after the ring-plane crossing, Cassini completely scanned across the rings with its radio science experiment in order to study their structure in detailed manner.

"It's taken years of planning, but now that we're finally here, the whole Cassini team is excited to begin studying the data that come from these ring-grazing orbits," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, California.

"This is a remarkable time in what's already been a thrilling journey," Spilker said.

Each of Cassini’s orbits for the remaining mission will last for one week.

The planning for the next pass by the rings is scheduled for December 11.

Cassini has been touring the Saturn system since arriving there in 2004 for an up-close study of the planet, its rings and moons. Since then, the spacecraft has delivered some amazing science, including a glorious view of Saturn and large lakes of liquid methane on the Moon Titan.

(With Ageny inputs)