Well, here we are. After 293 orbits of Saturn and more than 3,000 scientific papers, Cassini has finally sent its somber farewell. But it will leave behind it a vast and incredible legacy of discovery that shook our understanding of our place in the universe.
At 7.55am EDT (12.55pm BST), Cassini sent its final transmission to Earth. While we'll never know for sure what happened next, it's predicted that the spacecraft then broke apart about a minute later as it traveled into the atmosphere of Saturn. Its final swan song was a streak of light as it was destroyed at the end of its Grand Finale mission.
“The spacecraft's final signal will be like an echo,” Earl Maize, Cassini project manager at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, said in a statement.
Cassini was purposefully destroyed because, as it runs out of fuel, scientists don’t want the spacecraft to accidentally crash onto one of Saturn’s moons that could host life. Ironically, it’s thanks to Cassini that we know some of these moons could be habitable.
But in its 13 years orbiting Saturn, the mission has been an astounding success. Discovery after discovery has told us incredible things about Saturn and its moons, and let’s not forget the cavalcade of pictures we have been treated to for more than a decade.
The idea for the Cassini mission was first dreamed up in 1975 when the US National Research Council (NRC) suggested an in-depth exploration of the Saturnian system. By 1982, a proposal to develop a Saturn orbiter and Titan probe was submitted to NASA and ESA, called Project Cassini.
The project itself marked a shift in US-European relations. Europe’s close ties with Russia had pushed them away from the US, but this mission promised to mend some of their differences. That was one of the reasons it was able to survive several challenges in Congress in the early 1990s.
“The successful launch of Cassini-Huygens was regarded as a miracle by some involved in the mission,” notes US-European Collaboration in Space Science. “The mission was very ambitious and its implementation was risky.”
Ambitious was certainly the word. Cassini would not only become the first spacecraft to ever orbit Saturn, it would also carry a small lander – the Huygens probe. This would attempt to touch down on Saturn’s largest moon, Titan, regarded as one of the most Earth-like places in the Solar System.
On October 15, 1997, the Cassini-Huygens mission lifted off on board a Titan IVB rocket from Cape Canaveral in Florida. Following flybys of Venus, Earth, and Jupiter, it finally arrived at the Saturnian system on July 1, 2004, to uncover its secrets. And few could have predicted what it would discover.