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The Cassini

Date: Fri Apr 19 17:12:45 1996
Posted by: Joey Dayan
Grade level: 7-9
School/Organization: S.S.D.S
City: E.Brunswick State/Province: NJ
Country: U.S.A
Area of science: Astronomy


Dear , I am a student that is working on finding out information on the Cassini that Nasa will launch. There will be plutonium aboard the ship. I would like to know what will Nasa and all of us be risking and what will we benifit from this. I would also like to know what are Cassinis jobs to do in space. Thank you, Joey Dayan

The Cassini probe to Saturn is one of NASA's last ambitious planet probes. The scheduled launch is in October of 1997 using a Titan IV-Centaur rocket. 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 June 2004. The gravity assists act as a sort of sling shot, giving the probe the velocity it needs to get to Saturn.

The Cassini mission is very ambitious-- it will photograph Saturn and its moons, and drop a probe (called Huygens, pronounced Hoy-gins) into the atmosphere of Titan. The probe will study the atmosphere and use radar to map the surface of the moon. Cassini will study Saturn closely, looking at Saturn's ring system, its magnetic field, and its atmosphere (to determine composition, wind speed and heat sources), just to name some of the mission objectives.

The sunlight at Saturn is too dim to use solar panels, so a set of radioisotope thermoelectric generators (RTG) will be used. These use heat from the natural decay of plutonium to generate electricity to run Cassini. The plutonium is sealed in a chamber that has undergone extraordinarily rigorous testing, to ensure that even in a worst case scenario -- the crash or explosion of the rocket while still in the Earth's atmosphere -- the chamber will not leak. Some people were concerned that the Galileo Jupiter probe, which also used RTG's, might actually impact the Earth during one of its two flybys, but the odds of that were extremely small (calculated to be about one part in two million!). Cassini has similar odds.

Just so you know, The mission is named after Gian Domenico Cassini, an Italian astronomer who found a large gap in Saturn's rings, and the Titan probe is named after Christian Huygens, who discovered Titan. Cassini will return something like 2 trillion bits of information-- the equivalent of about 800 sets of the Encyclopedia Britannica!

This information was culled from many sources, including the NASA Cassini home page and the Jet Propulsion Labs Cassini page. Any incorrect info is my fault, not NASA's or JPL's!

©2008 Phil Plait. All Rights Reserved.

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