Apr 16, 2000

Cassini Survives the Asteroid Belt


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April 17, 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.

Right: A schematic diagram of the asteroid belt. [more information from the Goddard Space Flight Center]


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


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space out there," said Cassini Project Manager Bob Mitchell at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

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.
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Left: This image of asteroid Masursky was captured by Cassini on January 23,2000 at 3:01 UTC. [more information from JPL]

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.


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Right: This artist's rendering shows the Huygens Probe descending toward Titan's surface. The Cassini spacecraft flies overhead with Saturn appearing dimly in the background. The size of the orbiter, the sharpness of the icy features, the tilt of Saturn's rings, and the visibility of the planet through Titan's atmosphere have all been exaggerated through the use of artistic license. [more images from JPL]

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. Cassini's dish-shaped high-gain antenna was provided for the mission by the Italian Space Agency.


The mission is managed by JPL, a division of the California Institute of Technology. More information about the Cassini mission is available at

Web LinksCassini -- Mission to Saturn -- the mission home page hosted by JPL