June 3, 2004

Donald Savage
Headquarters, Washington
(Phone: 202/358-1547)

Carolina Martinez
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-9832)

RELEASE: 04-166

CASSINI WILL UNLOCK SATURN'S SECRETS

The international Cassini-Huygens mission is poised to begin an 
extensive tour of Saturn, its majestic rings and 31 known moons. 
After nearly a seven-year journey, Cassini is scheduled to enter 
orbit around Saturn at 10:30 p.m. EDT, June 30, 2004. 

"The Saturn system represents an unsurpassed laboratory, where we can 
look for answers to many fundamental questions about the physics, 
chemistry, evolution of the planets and the conditions that give rise 
to life," said Dr. Ed Weiler, NASA's Associate Administrator for 
Space Science, Washington.

Cassini was launched Oct. 15, 1997 on a journey covering 3.5 billion 
kilometers (2.2 billion miles), Cassini is the most instrumented and 
scientifically capable planetary spacecraft ever flown. There are 12 
instruments on the Cassini orbiter and six on the Huygens probe. The 
mission represents the best technical efforts of 260 scientists from 
the United States and 17 European nations. The Cassini mission cost 
approximately $3 billion.

The Cassini/Huygens mission is a four-year study of Saturn. The 18 
highly sophisticated science instruments will study Saturn's rings, 
icy satellites, magnetosphere, and Titan, the planet's largest moon. 

The spacecraft will fire its main engine for 96 minutes during the 
critical Saturn Orbit Insertion (SOI) maneuver. The maneuver will 
reduce Cassini's speed, so Saturn can capture it as an orbiting 
satellite. Cassini will pass through a gap between the planet's F and 
G rings, swing close to the planet, and begin the first of 76 orbits 
around Saturn's system. During the mission, it will have 52 close 
encounters with seven of Saturn's 31 moons.

There are risks involved with orbit insertion, but mission planners 
have prepared for them. There is a backup in case the main engine 
fails, and the path through the ring plane was searched for hazards 
with the best Earth and space-based telescopes. Particles too small 
to be seen from Earth could be fatal to the spacecraft, so Cassini 
will turn to use its high gain antenna as a shield against small 
objects. 

Saturn is the sixth planet from the sun, and it is the second largest 
in the solar system, after Jupiter. Saturn and its ring system serve 
as a miniature model for the disc of gas and dust that surrounded the 
early sun, which formed the planets. Detailed knowledge of the 
dynamics of interactions among Saturn's elaborate rings and many 
different moons will provide valuable data for understanding how the 
solar system's planets evolved.

The study of Titan, Saturn's largest moon, is one of the major goals 
of the mission. Titan may preserve, in deep-freeze, many of the 
chemical compounds that preceded life on Earth. Cassini will execute 
45 flybys of Titan within approximately 950 kilometers (590 miles) of 
the surface. This will permit high-resolution mapping of the moon 
with the Titan radar-imaging instrument. The radar can see through 
the opaque haze of Titan's upper atmosphere. 

"Titan is like a time machine taking us to the past to see what Earth 
might have been like," said Dr. Dennis Matson, Cassini project 
scientist at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif. 
"The hazy moon may hold clues to how the primitive Earth evolved into 
a life-bearing planet," he said. 

On Dec. 24, 2004, Cassini will release the wok-shaped Huygens probe 
for its journey to Titan. Huygens is the first probe designed to 
descend to the surface of the moon of another planet, and the most 
distant descent of a robotic probe attempted on another object in the 
solar system. On Jan. 14, 2005, after a three-week ballistic 
freefall, Huygens will enter Titan's atmosphere. It will deploy 
parachutes and begin 2.5 hours of intensive scientific observations. 
The Huygens probe will transmit data to the Cassini spacecraft, which 
will relay the information back to Earth.

JPL designed, developed and assembled the Cassini orbiter. A team at 
the European Space Technology and Research Center in Noordwijk, the 
Netherlands, managed the development of the Huygens probe. The 
Italian Space Agency provided the high-gain antenna, much of the 
radio system and elements of several of Cassini's science 
instruments. JPL manages the overall program for NASA's Office of 
Space Science. 

For information about the Cassini-Huygens mission to Saturn and Titan 
on the Internet, visit: 

http://www.nasa.gov/cassini
and 
http://saturn.jpl.nasa.gov 

	
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