Cassini, the great explorer of Saturn and one of my best friends these past 13 years, is dying.
Cassini launched in 1997 and entered orbit of Saturn on July 1, 2004.
The mission was only supposed to last six years, a limit set by the fuel the spacecraft carried for navigating around the Saturn system. But the mission controllers got so good at steering the craft using the gravitational tug of the planet and its moons that they have sent Cassini wherever they wanted for seven more years, and thankfully Congress found the money to keep its operators on the job.
These pictures show the results of that cleverness.
Here is Saturn in natural color, showing its golden glow.
But all good things must come to an end. Cassini is running out of fuel at last, and the controllers are running out of more science to do with its limited set of instruments and more images to take with its amazing cameras.
So on September 15 Cassini is set for a fiery end, diving into Saturn's atmosphere. It will keep broadcasting until it is crushed or otherwise destroyed, and scientists are hoping to learn more about Saturn from this final descent.
What an astonishing 13-year mission this has been.
The great robotic space voyages have been key markers of my life: Viking to Mars, Voyager 1 and 2 to Jupiter, Saturn, and beyond; the Mars Reconnaissance Orbiter; the Mars rovers; Galileo to Jupiter; New Horizons to Pluto.
Through them we have seen far distant worlds; through them our our universe has grown.
So on the eve of its death I honor Cassini, a noble member of this small band of great explorers, and the thousands of people who made it fly.