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Cassini
Table of Contents
- Cassini Spacecraft Introduction (This Page)
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Circled by distinctive
rings and attended by a group of at least 18 moons, Saturn has been
called one of the most intriguing planetary realms in the solar
system. Its largest moon, Titan, boasts organic chemistry that may
hold clues to how life formed on the primitive Earth. So it is that
Saturn and Titan will be the destination of the Cassini mission,
a project under joint development by NASA, the European Space Agency
and the Italian Space Agency. The U.S. portion of the mission is
managed for NASA by the Jet Propulsion Laboratory. Cassini's principal
objectives are:
- determine the three-dimensional structure and dynamical behavior
of the rings;
- determine the composition of the satellite surfaces and the
geological history of each object;
- determine the nature and origin of the dark material on Iapetus'
leading hemisphere;
- measure the three-dimensional structure and dynamical behavior
of the magnetosphere;
- study the dynamical behavior of Saturn's atmosphere at cloud
level;
- study the time variability of Titan's clouds and hazes; and,
- characterize Titan's surface on a regional scale.
Cassini was launched on October 15, 1997 atop a Titan IV-Centaur
rocket from Cape Canaveral, Florida. Cassini will first execute
two gravity-assist flybys of Venus, then one each of the Earth and
Jupiter to send it on to arrive at Saturn in July 2004. Upon reaching
Saturn, Cassini will swing close to the planet -- to an altitude
only one-sixth the diameter of Saturn itself -- to begin the first
of some five dozen orbits during the rest of its four-year mission.
In late 2004, the spacecraft will release the European-built Huygens
probe for its descent of up to two-and-a-half hours through the
dense atmosphere of Saturn's moon Titan. The instrument-laden probe
will beam its findings to the Cassini orbiter to be stored and finally
relayed back to Earth. During the course of the Cassini orbiter's
mission, it will perform some three dozen close flybys of particular
bodies of interest -- including more than 30 encounters of Titan
and at least four of selected icy satellites of greatest interest.
In addition, the orbiter will make at least two dozen more distant
flybys of the Saturian moons. Cassini's orbits will also allow it
to study Saturn's polar regions in addition to the planet's equatorial
zone.
Cassini Orbiter and
Huygens Probe aboard the Titan IV
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At Launch Complex 40 on Cape Canaveral Air Station, the Mobile
Service Tower has been retracted away from the Titan IVB/Centaur
carrying the Cassini spacecraft. The launch vehicle, Cassini spacecraft
and attached Centaur stage encased in a payload fairing, altogether
stand about 183 feet tall; mounted at the base of the launch vehicle
are two upgraded solid rocket motors.
Launch of Cassini Orbiter
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A seven-year journey to the ringed planet Saturn begins with
the liftoff of a Titan IVB/Centaur carrying the Cassini orbiter
and its attached Huygens probe. Launch occurred at 4:43 a.m. EDT,
October 15, 1997 from Launch Complex 40 on Cape Canaveral Air Station.
Cassini Orbiter and Huygens Probe aboard
the Titan IV
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After a 2.2-billion mile journey that will include two swingbys
of Venus and one of Earth to gain additional velocity, the Cassini
spacecraft will arrive at Saturn in July 2004. The orbiter will
circle the planet for four years, its complement of 12 scientific
instruments gathering data about Saturn's atmosphere, rings and
magnetosphere and conducting closeup observations of the Saturnian
moons. Huygens, with a separate suite of six science instruments,
will separate from Cassini to fly on a ballistic trajectory toward
Titan, the only celestial body besides Earth to have an atmosphere
rich in nitrogen. Scientists are eager to study further this chemical
similarity in hopes of learning more about the origins of our own
planet Earth. Huygens will provide the first direct sampling of
Titan's atmospheric chemistry and the first detailed photographs
of its surface.
Cassini (1997)
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This artist's rendering depicts the NASA/JPL Cassini spacecraft
in orbit around ringed Saturn (lower right background). At the lower
left, the European Space Agency's Huygens probe descends to the
surface of Saturn's moon Titan (in foreground).
Huygens
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This artist's rendering shows the European Space Agency's Huygens
probe descending into the atmosphere of Saturn's moon Titan after
being released by NASA's Cassini spacecraft.
Huygens
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This artist's rendering shows the European Space Agency's Huygens
probe descending into the atmosphere of Titan with Saturn in the
background.
Huygens on Titan's Surface
This artist's rendering shows the Huygens probe on the surface of
Titan.
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