Cassini at Saturn: A Personal 32 Year Journey

In this installment of the Accretion Desk, I have put together some of the experiences I have collected over the years with the Cassini spacecraft. For me the upcoming four-year mission around Saturn only adds more enjoyment to my personal Saturn experience, one that began formally 32 years ago.

Steve Edberg (left), the outreach manager for the Cassini mission, and myself pose for a picture in a cleanroom at the Jet Propulsion Lab (JPL). Standing in front of a full-scale mockup of the Cassini spacecraft, it is inspiring to think that this huge machine will cause a rewrite of all the astronomy textbooks in the world.

Saturn has always been the planet of my dreams. Although the earth does hold a special place in my heart, mostly because I was born there, Saturn truly captured my interest and imagination even as young kid. I can think of no other amateur astronomical experience more vivid and enlightening than for the first time, gazing at the Lord of the Rings through a telescope. I can remember being surprised that it looks just like the pictures!

Back when I was in third grade, some 32 years ago, I wrote an eight-page story about traveling to Saturn. The planet simply is, and always has been my favorite. It is just too bad there there will likely never be any meteorites associated with it.

Seems that I was not the only one with a fondness for Saturn. NASA and the JPL too were interested in the ringed giant as well launching a $3.3 billion ($3,300,000,000!) Cassini spacecraft to Saturn in October 1997. Cassini’s launch seems so long ago, but the seven-year journey is now over, and the two-story tall, 5500kg, nuclear powered space probe has gone into orbit around Saturn. Its four-meter diameter high-gain antenna will blast back to earth shocking images destined to rewrite all astronomy textbooks that dared to share the pittance of information we had about the wild gaseous world and its moons. No chance for a failed antenna deployment like Galileo, Cassini’s dish is solid, fixed, and covers one entire end of the spacecraft.

Another picture of the behemoth with the 4-meter diameter dish on the top. A goal of the design of this amazing machine was to have as few moving parts as possible. For that reason, the plethora of science instruments are pretty much fixed meaning that essentially the entire spacecraft must rotate to point the desired instrument at the desired target.


At the JPL on August 17, 1999, the big event was the Cassini Earth Flyby. Posing with me is Nancy Tashima, a very dear friend who is also the director of Onizuka Space Science Center in Kona, Hawaii. If you don’t think that the JPL has a sense of humor, check out the next encounters for the two Voyager spacecraft on the billboard’s upper right.


The Cassini Earth Flyby was marked by a standing-room-only press conference at the JPL. Since Cassini contains three radioisotope thermal generators, called RTGs and are powered by plutonium, justifiable concern was apparent (but not at the JPL) that a navigation error or some other problem would cause Cassini to return home dispersing is nuclear payload into our atmosphere along the way. Of course Cassini behaved herself and continued on her way to Saturn. This picture is at the press conference in the Von Karman auditorium at the JPL. Notice the commemorative Cassini-Huygens Earth Swingby tee shirt in the front row-right, and the countdown clock just above the tee shirt. Nancy and I have the same tee shirt in the above billboard picture as well.


In this closeup picture of the Cassini clock, you can see that the Earth Closest Approach clock (the bottom one) has turned to zero meaning that at the moment this picture was taken, the nuclear powered Cassini spacecraft is as close to earth as it will ever get again since its launch on October 15, 1997.


Talking to Cassini looks like this. This computer bank is at the Goldstone Deep Space Network (DSN) near Barstow, California. Goldstone is one of three DSN sites spaced roughly 120 degrees apart around the earth (three times 120 degrees equals 360 degrees or a complete circle).


Behind me is a 34-meter radio dish at the Goldstone DNS site. This dish, one of many, is used to send and receive data at the speed of light across the billions of kilometers of space.

So now the real fun begins as the mysteries of Saturn are unraveled, and new mysteries take their place. Thank goodness that NASA and the JPL are full of dreamers. Without them, the dreams of this big kid would never be realized. Godspeed Cassini!

About the Author

Dr. Martin Horejsi is a Professor of Instructional Technology and Science Education at The University of Montana. A long-time meteorite collector and writer, before publishing his column The Accretion Desk in The Meteorite Times, he contributed often and wrote the column From The Strewnfields in Meteorite Magazine. Horejsi is currently a monthly columnist in The Science Teacher, a journal by the National Science Teachers Association.Horejsi specializes in the collection and study of historic witnessed fall meteorites with the older, smaller, and rarer the better. Although his meteorite collection once numbered over a thousand pieces with near that many different locations, several large trades and sales have streamlined the collection to about 250 locations with all but 10 being important witnessed falls.Many of the significant specimens in Horejsi's collection are historic witnessed falls that once occupied prominence in the meteorite collections of Robert A. Haag, James Schwade, and Michael Farmer. Other important specimens were acquired through institutional trades including those from The Smithsonian Institution, Arizona State University, and other universities.

Meteorite Times Magazine