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<DIV>April 15, 2008<BR></DIV>
<DIV>RELEASE: 08-098<BR><BR>NASA EXTENDS CASSINI'S GRAND TOUR OF
SATURN<BR><BR>PASADENA, Calif. -- NASA is extending the international
<BR>Cassini-Huygens mission by two years. The historic spacecraft's <BR>stunning
discoveries and images have revolutionized our knowledge of <BR>Saturn and its
moons.<BR><BR>Cassini's mission originally had been scheduled to end in July
2008. <BR>The newly-announced two-year extension will include 60 additional
<BR>orbits of Saturn and more flybys of its exotic moons. These will <BR>include
26 flybys of Titan, seven of Enceladus, and one each of <BR>Dione, Rhea and
Helene. The extension also includes studies of <BR>Saturn's rings, its complex
magnetosphere, and the planet itself. <BR><BR>"This extension is not only
exciting for the science community, but <BR>for the world to continue to share
in unlocking Saturn's secrets," <BR>said Jim Green, director, Planetary Science
Division, NASA <BR>Headquarters, Washington. "New discoveries are the hallmarks
of its <BR>success, along with the breathtaking images beamed back to Earth that
<BR>are simply mesmerizing."<BR><BR>"The spacecraft is performing exceptionally
well and the team is <BR>highly motivated, so we're excited at the prospect of
another two <BR>years," said Bob Mitchell, Cassini program manager at NASA's Jet
<BR>Propulsion Laboratory in Pasadena, Calif.<BR><BR>Based on findings from
Cassini, scientists think liquid water may be <BR>just beneath the surface of
Saturn's moon, Enceladus. That's why the <BR>small moon, only one-tenth the size
of Titan and one-seventh the size <BR>of Earth's moon, is one of the
highest-priority targets for the <BR>extended mission. <BR><BR>Cassini
discovered geysers of water-ice jetting from the Enceladus' <BR>surface. The
geysers, which shoot out at a distance three times the <BR>diameter of
Enceladus, feed particles into Saturn's most expansive <BR>ring. In the extended
mission, the spacecraft may come as close as 15 <BR>miles from the moon's
surface.<BR><BR>Cassini's observations of Saturn's largest moon, Titan, have
given <BR>scientists a glimpse of what Earth might have been like before life
<BR>evolved. They now believe Titan possesses many parallels to Earth,
<BR>including lakes, rivers, channels, dunes, rain, snow, clouds, <BR>mountains
and possibly volcanoes.<BR><BR>"When we designed the original tour, we really
did not know what we <BR>would find, especially at Enceladus and Titan," said
Dennis Matson, <BR>the JPL Cassini project scientist. "This extended tour is
responding <BR>to these new discoveries and giving us a chance to look for
more." <BR><BR>Unlike Earth, Titan's lakes, rivers and rain are composed of
methane <BR>and ethane, and temperatures reach a chilly minus 290 degrees
<BR>Fahrenheit. Although Titan's dense atmosphere limits viewing the
<BR>surface, Cassini's high-resolution radar coverage and imaging by the
<BR>infrared spectrometer have given scientists a better look.<BR><BR>Other
activities for Cassini scientists will include monitoring <BR>seasons on Titan
and Saturn, observing unique ring events, such as <BR>the 2009 equinox when the
sun will be in the plane of the rings, and <BR>exploring new places within
Saturn's magnetosphere.<BR><BR>Cassini has returned a daily stream of data from
Saturn's system for <BR>almost four years. Its travel scrapbook includes nearly
140,000 <BR>images and information gathered during 62 revolutions around Saturn,
<BR>43 flybys of Titan and 12 close flybys of the icy moons.<BR><BR>More than 10
years after launch and almost four years after entering <BR>into orbit around
Saturn, Cassini is a healthy and robust spacecraft. <BR>Three of its science
instruments have minor ailments, but the impact <BR>on science-gathering is
minimal. The spacecraft will have enough <BR>propellant left after the extended
mission to potentially allow a <BR>third phase of operations. Data from the
extended mission could lay <BR>the groundwork for possible new missions to Titan
and Enceladus.<BR><BR>Cassini launched Oct. 15, 1997, from Cape Canaveral, Fla.,
on a <BR>seven-year journey to Saturn, traversing 2.2 billion miles. It is one
<BR>of the most scientifically capable spacecraft ever launched, with a
<BR>record 12 instruments on the orbiter and six more instruments on the
<BR>European Space Agency's Huygens probe, which piggybacked a ride to <BR>Titan
on Cassini. Cassini receives electrical power from three <BR>radioisotope
thermoelectric generators, which generate electricity <BR>from heat produced by
the natural decay of plutonium. The spacecraft <BR>was captured into Saturn
orbit in June 2004 and immediately began <BR>returning data to Earth.<BR><BR>The
Cassini-Huygens mission is a cooperative project between NASA, the <BR>European
Space Agency and the Italian Space Agency.<BR><BR>For more information on the
Cassini-Huygens mission, visit:<BR><BR><A
href="http://www.nasa.gov/cassini">http://www.nasa.gov/cassini</A></DIV></BODY></HTML>