NASA’s Cassini spacecraft is in the midst of evasive maneuvers that will lift it out of Saturn’s ringplane and prepare it for a February 1 encounter with its moon Titan, officials from the US space agency confirmed on Monday.
On Saturday, Cassini underwent the second of five large propulsive maneuvers that will change the spacecraft’s orbit, bringing it to increasingly higher inclination with respect to the equator of the planet and preparing it for the upcoming gravity-assisted flyby of Titan.
Tethys, dwarfed by the scale of Saturn and its rings, appears as an elegant crescent in this image taken by NASA’s Cassini Spacecraft. Views like this are impossible from Earth, where we only see Saturn’s moons as (more or less) fully illuminated disks. (Credit: NASA/JPL-Caltech/Space Science Institute)
This weekend’s maneuver started at 5:47pm EST and lasted just 35 seconds, but during that time the orbital velocity of the spacecraft around Saturn changed by roughly 22.3 feet per second (6.8 meters per second). Next week’s encounter with Titan will alter Cassini’s speed by an additional 2,539 feet per second (774 meters per second), according to agency officials.
“Titan does all the heavy lifting,” Cassini project manager Earl Maize from NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a statement. “Our job is to get the spacecraft to a precise altitude and latitude above Titan, at a particular time, and these large propulsive maneuvers are what keep us on target to do that.”
Getting set for the mission’s September 2017 coup de grace
NASA said that there are no plans for Cassini to return to an orbit near the ringplane. Rather, mission engineers are gradually increasing its orbital tilt relative to Saturn’s equator to prepare for the final year of the mission, which has studied the system for more than a decade.
Cassini has been in an equatorial orbit around Saturn since last spring, when it kicked off its final run of near flybys with the large, icy moons Hyperion, Dione and Enceladus. Just before the start of the new year, the spacecraft started its current program through a burn that changed its speed by 9.8 feet per second (3 meters per second) prior to a January 15 flyby of Titan.
Although the Huygens probe has now pierced the murky skies of Titan and landed on its surface, much of the moon remains for the Cassini spacecraft to explore. Titan continues to present exciting puzzles. This view of Titan uncovers new territory not previously seen at this resolution by Cassini’s cameras. The view is a composite of four nearly identical wide-angle camera images. (Credit: NASA/JPL/Space Science Institute)
The next main engine maneuver is scheduled for March 25, and will set up an final April 4 flyby of Titan by changing Cassini’s velocity by 26.08 feet (7.95 meters) per second. Before the end of November, Cassini will be on a path that will carry it high above Saturn’s poles, approaching just beyond the planet’s main rings. This phase of the mission has been dubbed “F-ring orbits.”
After completing 20 of these F-ring orbits, the spacecraft will begin the final leg of its mission as it will pass between the Saturn’s innermost rings and the planet’s surface 22 times before it dives into the atmosphere on September 15, 2017. Even though this will culminate in the coup de grace for the mission, Cassini scientist Linda Spilker of JPL noted that NASA has “an exciting year of Saturn science planned” and that “views along the way should be spectacular.”
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Feature Image: NASA/JPL
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