NASA Cassini Spacecraft Begins Ring-Grazing Orbits Phase Of Saturn Mission
A thrilling ride for the Cassini spacecraft of NASA is in store starting Nov. 30 as the mission enters the critical phase of its endgame after being nudged by a gravitational push from Saturn's moon Titan.
Engineers were successful in adjusting the spacecraft's orbit around Saturn for expanding the tilt in sync with the equator and Saturn's rings.
According to NASA, between Nov. 30 and April 22, Cassini will be circling high above Saturn but well under the poles.
During the motion, Cassini will dive every seven days through the unchecked regions of Saturn, including the outer edge of the main rings, to deliver new data.
Cassini's Ring Grazing Orbits
"We're calling this phase of the mission Cassini's Ring-Grazing Orbits, because we'll be skimming past the outer edge of the rings," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena.
The official said Cassini's vital instruments can sample particles and gases while crossing the ring plane and that makes Cassini really "grazing" on the rings.
Cassin's ring grazing will expose it to particles of gases near the rings. During the orbiting, Cassini will also strike two small moons named Janus and Epimetheus as it passes a faint ring.
Grazing the ring edges will mean advantages of close encounters with the outer portions of Saturn's main rings such as the A, B and F rings.
Coming Close To The F Ring
In March and April, the ring crossings will take the spacecraft closer to the dusty reaches of the F ring, which will be the closest range a NASA mission has ever come.
"Even though we're flying closer to the F ring than we ever have, we'll still be more than 4,850 miles (7,800 kilometers) distant," pointed out Earl Maize, Cassini's project manager at JPL.
The F ring is considered more complex with many Cassini images showing bright streamers, dark channels and wispy filaments appearing fleetingly.
According to experts, Cassini's ring-grazing orbits will help in observing many small moons that are orbiting the rings, including Pandora, Daphnis, Atlas and Pan.
Cassini's investigation will also cover the A ring's "propellers" to reveal more about the presence of unseen moonlets.
Cassini's End Of Life
What makes Cassini's orbits grazing more significant is that it precedes the mission's demise in September 2017. After the orbit grazing for five months, Cassini will enter its "grand finale" and eventually fall into the planet's atmosphere in September 2017.
Cassini arrived at Saturn in 2004 after its launch in 1997 for an up-close study of the planet and its rings. The spacecraft is already credited with many discoveries, including an ocean within Enceladus and liquid methane sea on Titan.