NASA’s spacecraft Cassini launched almost 20 years ago. In two decades of its 2.2 billion mile interplanetary voyage it has accomplished major scientific breakthroughs. Today, it is exploring the beautiful rings of Saturn before the end of its mission planned for September 15 this fall, when NASA has scheduled it to burn up in that planet’s atmosphere.
Cassini’s launch from Cape Canaveral was October 15, 1997, in the second term of President Clinton’s administration. The momentous events of that year put the mission’s duration in perspective. England handed over Hong Kong to China. Scientists in Scotland cloned Dolly the sheep. Also, Timothy McVeigh was found guilty of the Oklahoma City federal building bombing.
Millions of mourners gathered outside a London cathedral for the funeral of Princess Diana. And, Tony Blair become prime minister of Great Britain in a landslide election victory, ending 18 years of Conservative rule.
The spacecraft’s design included a Saturn orbiter (Cassini) and a lander (Huygens) for the moon Titan. The spacecraft launched atop a Titan IVB/Centaur rocket and entered orbit around Saturn on July 1, 2004, after an interplanetary voyage that included flybys of Earth, Venus, and Jupiter.
On December 25, 2004, Huygens separated from the orbiter, and landed on Saturn’s moon Titan on January 14, 2005. It successfully returned data to Earth, using the orbiter as a relay (at the speed of light, these transmissions took 85 minutes for the signal to reach NASA scientists).
Cassini continued to study Saturn and its moons for the next 13 years, and continues to operate as of today. However, since November of last year, due to the spacecraft’s dwindling fuel resources for further orbital corrections, Cassini entered the final phase of the project.
Going forward between now and mid-September, Cassini will dive through the outer ring of Saturn 22 times, once every seven days. The spacecraft will enter areas that have been untouched up until this point (unless some ET UFOs have been there before us), getting the closest look ever of Saturn’s outer rings.
The first pass through the rings took place in December of last year when Cassini skimmed 1,900 miles above Saturn’s cloud tops, closer than ever before, and came within 200 miles of the innermost visible ring, all the while beaming back spectacular images of the planet and its rings.
Some of the upcoming passages of the rings will bring Cassini even closer to the planet as well as to the innermost, mysterious “D ring.” The gap between the rings and the top of Saturn’s atmosphere is between 1,200 and 1,500 miles across. It will be a daunting mission.
Cassini’s dancing through the rings at 76,800 miles per hour is perilous indeed, as the rings consist of icy pellets which could damage the spacecraft. But, so far, the closer exploration of the rings has been a total success.
NASA’s current plan is that Cassini will be destroyed by diving into the planet’s atmosphere on September 15, 2017, when it will beam back its last batch of images. The decision to end Cassini’s mission in 2017 was made to prevent the spacecraft from crashing into and damaging any of Saturn’s 62 moons.
Between its 1997 launch and “mission complete” later this year, Cassini’s remarkable mission has advanced scientific frontiers to our outer solar system. Scientists continue to analyze the mountains of data that the spacecraft has beamed back to Earth.
Meanwhile, as we await the ultimate fate of Cassini next fall, we should extend our hearty congratulations to the entire Cassini team of over 5,000 scientists, engineers, astrophysicists, technicians, and others at NASA for a job well done. It is another example of American exceptionalism in the amazing arena of space exploration.