Cassini to accommodate ‘spectacular end’ – Tribune

Updated 5 hours ago


CAPE CANAVERAL, Fla. — NASA’s Cassini booster faces one final hazardous journey around Saturn.

Cassini swung past Saturn’s mega moon Titan early Saturday for a gravity-assisted, orbit-tweaking nudge.

“That final lick goodbye,” as plan manager Earl Maize calls it, will pull Cassini onto a trail no booster has left before — into a opening between Saturn and a rings. It’s fraudulent territory. A molecule from a rings — even as tiny as a pinch of silt — could ravage Cassini, given a velocity.

Cassini will make a initial pass by a comparatively slight opening Wednesday. Twenty-two crossings are planned, about one a week, until September, when Cassini goes in and never comes out, vaporizing in Saturn’s atmosphere.

Launched in 1997, Cassini reached Saturn in 2004 and has been exploring it from circuit ever since. Its European roving companion, Huygens, landed on Titan in 2005. Cassini’s fuel tank is most empty, so with tiny left to lose, NASA has opted for a risky, though science-rich grand finale.

“What a fantastic finish to a fantastic mission,” pronounced Jim Green, NASA’s heavenly scholarship multiplication director. “I feel a tiny unhappy in many ways that Cassini’s discoveries will end. But I’m also utterly confident that we’re going to learn some new and unequivocally sparkling scholarship as we examine a segment we’ve never probed before.”

There’s no branch behind once Cassini flies past Titan, Maize said. The booster on Wednesday will run by a 1,200-mile-wide opening between Saturn’s atmosphere and a rings, during a breakneck 70,000-plus mph.

From a navigation standpoint, “this is an easy shot,” Maize said. The operation will be run from NASA’s Jet Propulsion Laboratory in Pasadena, Calif. The regard is either mechanism models of Saturn’s rings are accurate. On a few of a crossings, Cassini is “kind of flirting with a corner of where we consider it’s safe,” he noted.

For during slightest a initial outing by a gap, Cassini’s large plate receiver will face brazen to defense a scholarship instruments from any ring particles that competence be sneaking there. A integrate instruments will yield a discerning outline on a dirt situation.

Scientists expect lots of lightweight impacts, given a booster will be going by intensely tiny material, some-more like fume than graphic particles. Material from a innermost D ring — that is solemnly fluctuating into Saturn — should be disband adequate “that we should be fine,” Maize said.

If a models are wrong and Cassini is clobbered by BB-size material, it still will finish adult accurately where NASA is aiming for on Sept. 15 — Saturn. The space group wants to keep a 22-foot-high, 13-foot-wide booster divided from Titan and a lakes of glass methane and from a ice-encrusted moon Enceladus and a subterraneous sea and rising geysers. It doesn’t wish to showering contaminating disadvantage onto these worlds that competence bay life.

This final leg of Cassini’s 20-year, $3.27 billion excursion should concede scientists to magnitude a mass of a mixed rings — shedding light on how aged they are and how they shaped — and also to establish a combination of a large ring particles. First speckled by Galileo in 1610, a rings are believed to be 99 percent ice; a remaining 1 percent is a mystery, pronounced plan scientist Linda Spilker. A vast dirt analyzer on Cassini will drop adult ring particles and investigate them.

“Imagine a cinema we’re going to get behind of Saturn’s rings,” Spilker said.

Cassini will have a best views ever of Saturn’s poles, as it skims a surface. Near mission’s end, Spilker said, “we’re indeed going to drop a toe” into Saturn’s atmosphere, returning measurements until a final probable moment.

All this is on tip of a scholarship goal that already has rewritten a textbooks on a Saturnian system.

“But a best is still nonetheless to come — perhaps,” Maize pronounced during a news discussion in early April. “But we are positively going to yield some-more excitement.”


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