Cassini Passes Through Asteroid Belt

Cassini Passes Through Asteroid Belt

April 14, 2000

NASA's Cassini spacecraft, currently en route to Saturn, has successfully
completed its passage through our solar system's asteroid belt between Mars
and Jupiter.

This makes Cassini the seventh spacecraft ever to fly through the asteroid
belt. Before NASA's Pioneer 10 spacecraft successfully passed through the
region in 1972, it was not known whether a spacecraft could survive the trip.

The belt contains a significant concentration of asteroids. Nonetheless,
the area is not considered a hazard to spacecraft. Engineers did not make
any adjustments to Cassini as it passed through the region, except the
spacecraft's cosmic dust analyzer was reoriented whenever possible to
better study the environment. A cover over Cassini's main engines has
been in place at all times since launch except when main engine firings
were performed. The cover protects the engines from any possible impacts.

"I'm glad we've passed through it, but it's pretty routine. There's a
lot of material in the belt, but there's also an awful lot of space out
there," said Cassini Project Manager Bob Mitchell at NASA's Jet Propulsion
Laboratory, Pasadena, California.

The spacecraft entered the belt in mid-December and while it was in the
area, Cassini's camera imaged the asteroid 2685 Masursky. Data gathered
provided scientists with the first size estimates on the asteroid and
preliminary evidence that it may have different material properties than
previously believed.

Cassini remains in excellent health as it continues its seven-year-long
journey to Saturn. Launched October 15, 1997, Cassini has already flown by
Venus and Earth before heading toward a flyby of Jupiter on December 30, 2000.
The giant planet's gravity will bend Cassini's flight path to put it on
course for arrival into orbit around Saturn on July 1, 2004.

Cassini's mission is to study Saturn, its moons, its rings, and its
magnetic and radiation environment for four years. Cassini will also
deliver the European Space Agency's Huygens probe to parachute to the
surface of Saturn's moon Titan on November 30, 2004. Titan is of special
interest partly because of its many Earth-like characteristics, including a
mostly nitrogen atmosphere and the presence of organic molecules in the
atmosphere and on its surface. Lakes or seas of ethane and methane may
exist on its surface.

Additional information about Cassini is available online at:

http://saturn.jpl.nasa.gov.

The mission is a joint endeavor of NASA, the European Space Agency and the
Italian Space Agency. The Cassini orbiter, built by NASA, and the Huygens
probe, provided by the European Space Agency (ESA), were mated together and
launched as a single package from Cape Canaveral, Florida, on October 15, 1997.
Cassini's dish-shaped high-gain antenna was provided for the mission by the
Italian Space Agency.

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