JPL: NASA Extends Cassini's Mission 7 More Years

[bystander]

http://www.jpl.nasa.gov/news/news.cfm?release=2010-039

NASA will extend the international Cassini-Huygens mission to explore Saturn and its moons to 2017. The agency's fiscal year 2011 budget provides a $60 million per year extension for continued study of the ringed planet.

[RJN]

Great news!

[neufer]

http://www.jpl.nasa.gov/news/news.cfm?release=2010-039

Cassini's Extended Mission
by John Spencer February 24, 2009

<<Around Thanksgiving 2016 Cassini will be in an orbit which brings it as close as 3.63 Saturn radii from Saturn's center, between the orbits of Mimas and Enceladus. Then, on November 29, 2016 the spacecraft will use its penultimate Titan flyby to alter its orbit so that Saturn closest approach drops to 2.51 Saturn radii, just 10,000 kilometers beyond the narrow F ring, and not far from the outer edge of the main rings. Cassini will execute 20 of these close "F-ring" orbits before setting up for a final close Titan flyby on April 22, 2017.

This flyby will do something astonishing: it will perturb the orbit so that Saturn closest approach jumps, in a single leap, from just outside the main ring system into the narrow zone of safety between the inner edge of the innermost ring (the D ring) and the planet itself, just 3,800 kilometers above Saturn's cloud tops. Cassini will continue to thread this needle for 23 orbits (called, with some understatement, the "proximal" orbits) until a final distant nudge from Titan on September 11, 2017 delivers the death blow, altering the orbit just enough to drop Cassini into Saturn on September 15.

Cassini's end-of-mission "proximal" orbits

A schematic illustration of Cassini's final Saturn orbits in 2016 and 2017, according to the current XXM plan. The view is from directly above Saturn's north pole, with the main ring system shown in gray, and Cassini's path shown in black. The cluster of orbits crossing the lower part of the figure are the "F-ring" orbits which Cassini will follow from November 2016 to April 2017, and the upper cluster of orbits, passing between the rings and the planet, are the "proximal" orbits that will be followed from April 2017 until Saturn impact in September 2017. Credit: NASA / JPL

These final orbits will be an entirely new mission for Cassini, similar in many ways to the Juno mission, which will be executing a series of cloud-skimming orbits of Jupiter at about the same time. By coming so close to Saturn, we can map its gravity and magnetic field in exquisite detail, probing the planet's deep interior. By flying between the planet and the rings we can separate the gravitational effects of the rings from Saturn itself, providing for the first time a reliable estimate of the total mass of Saturn's ring system. Currently we don't know the mass of the rings, which is crucial for understanding their age and evolution, to better than a factor of ten. We should even be able to analyze the composition of Saturn's atmosphere directly with Cassini's mass spectrometer, as we have done in the past for the atmosphere of Titan and the plumes of Enceladus. This will be a fantastic way to end the mission.>>

[geckzilla]

How long will Cassini last in Saturn's cloud tops? Can't wait to see pictures.

[Beyond]

Wait a minute!! You mean its going to cost us $60,000,000 a year just to monitor and do adjusting of travel for a piece of equipment that is already there and paid for? Using equipment back here that is already paid for?

They sure must use a lot of electricity and pay very high wages!!!!

[bystander]

Hello, Saturn Summer Solstice: Cassini's New Chapter
NASA JPL | Cassini Solstice Mission | 27 Sept 2010

Turning a midsummer night's dream into reality, NASA's Cassini spacecraft begins its new mission extension -- the Cassini Solstice Mission -- today. The mission extension will take Cassini a few months past Saturn's northern summer solstice (or midsummer) through September 2017. It will enable scientists to study seasonal changes and other long-term weather changes on Saturn and its moons.

Cassini had arrived just after Saturn's northern winter solstice in 2004, and the extension continues a few months past the northern summer solstice in May 2017. A complete seasonal period on Saturn has never been studied at this level of detail.

Cassini has revealed a bounty of scientific discoveries since its launch in 1997, including previously unknown characteristics of the Earth-like world of Saturn's moon Titan, and the plume of water vapor and organic particles spewing from another moon, Enceladus.

The Cassini Solstice Mission will enable continued study of these intriguing worlds. It will also allow scientists to continue observations of Saturn's rings and the magnetic bubble around the planet, known as the magnetosphere. Near the end of the mission, the spacecraft will make repeated dives between Saturn and its rings to obtain in-depth knowledge of the gas giant. During these dives, the spacecraft will study the internal structure of Saturn, its magnetic fluctuations and ring mass.