Around 7:30 a.m. Friday morning, planet Earth will lose the Cassini spacecraft’s signal just before it takes that final, fiery plunge into Saturn’s atmosphere, marking the end of an amazing 13 years of exploration and nearly 30 years of preparation and work.
Launched in 1997, Cassini arrived in orbit around Saturn in 2004 on a mission to study the giant planet, its rings, moons, and magnetosphere. In April of this year, Cassini began the final phase of its mission, called its Grand Finale, consisting of a daring series of 22 weekly dives between the planet and its rings.
During the previous five months, Cassini has explored the uncharted territory between the gaseous planet and its rings, sending back astounding images that have been a source of wonderment to scientists and the general public alike. Cassini has touched the lives of many people, and quite a few have devoted their whole careers to pouring over Cassini’s data and making tiny course corrections from millions of miles away.
A final kiss goodbye
To get a gravity assist, Cassini flew by Saturn’s jumbo moon, Titan on Monday – a final kiss goodbye, as NASA calls it, nudging the spacecraft into a deliberate, no-way-out path. During its final plunge Friday morning, Cassini will continue to sample Saturn’s atmosphere, beaming back data, until the spacecraft loses control and its antenna no longer points toward Earth.
Descending at a scorching 76,000 mph (122,000 kph), Cassini will melt and then vaporize. It should be all over in a minute. “The mission has been insanely, wildly, beautifully successful, and it’s coming to an end,” said NASA program scientist Curt Niebur. “I find great comfort in the fact that Cassini will continue teaching us up to the very last second.”
And finding comfort in what has become almost a “living thing,” knowing it will end its life has been heart-wrenching to many in the space community. The accolades and praises for the Cassini program have been pouring into Twitter’s @CassiniSaturn page.
Sarah Hörst is a planetary scientist who studies Saturn’s moon Titan and has worked with the spacecraft’s data since she was in graduate school, according to Popular Science. “All of my research for the past 13 years has basically been inspired by Cassini in some part,” she says. “In that sense, I owe a huge chunk of my career to Cassini.”
“There’s something really beautiful about Cassini,” she says. “I think that one reason that people feel a connection to it, both within the planetary science community and outside of it, is that it’s a powerful spacecraft. You don’t have to love Saturn, you don’t have to think the rings are the greatest things, you don’t have to be a Titan person—though I don’t personally understand that—there’s something for everyone.”
Sadly, NASA has no plans to return to Saturn, but there is another mission in the works. The next big mission to the outer solar system will be the Europa Clipper, which will study a moon of Jupiter, bypassing Saturn. NASA’s Europa Clipper mission will investigate Jupiter’s moon Europa to determine whether the icy moon could harbor conditions suitable for life. The mission will take place in the 2020s.
Hörst sums everyone’s feeling up pretty good: “It was paid for by taxpayers from a number of countries, not just the United States. It was an international mission, an intergenerational mission. We’ve never had a mission like it, and It will likely be a while before we have another mission similar to it again.”
