Like all good things, epic space missions must come to an end. But in the case of NASA’s Cassini mission around Saturn, it’s going to end in dramatic style.
After a decade in orbit around the ringed gas giant Cassini has revolutionized our understanding of Saturn’s rings, moons and dynamic atmosphere. It’s even put Earth in its place, as a tiny blue dot in the vast expanse of space.
Sadly, Cassini can’t soldier on forever; it will run out of fuel (used by its thrusters for adjustments during orbit) — but that’s not necessarily a bad thing.
Until now, mission managers have tried to protect the spacecraft from any orbital risks in the interest of prolonging Cassini’s life, but as the mission is now coming to a close, they can afford to be a little less careful while looking for awesome science opportunities. Starting in 2016, Cassini will be commanded to carry out a “daring set of orbits that is, in some ways, like a whole new mission,” writes NASA in a recent news release.
Known as “proximal orbits,” the spacecraft will fly high above Saturn’s poles and then fly outside the planet’s narrow F-ring. This orbital path will take it past the icy moon Enceladus, allowing another passage through the moon’s fascinating water-rich plumes that blast into space.
Then, its trajectory will evolve to make a dive between the innermost ring and the planet 22 times. Flying through the ring plane will increase the potential for impacts with ring dust, ice grains and even large rocks, so until now such an orbital profile has been avoided at all costs.
What happens next? Well, assuming it doesn’t hit anything in the meantime, to avoid an end-of-mission collision with Titan or Enceladus — two Saturnian moons with biological potential that scientists do not want to contaminate with any hardy Earth-borne bacteria that may be hitching a ride on the probe — Cassini will plunge into Saturn’s atmosphere, burning up in a fiery final act.
Now that the mission is entering a very final and distinct phase of its decade-long Saturn odyssey, NASA has asked for mission-naming ideas. After the Cassini’s primary mission, it was renamed “Cassini Equinox” (2008) then “Cassini Solstice” (2010) after each mission extension, which related to the changing seasons on Saturn. Now, after considering suggestions from 2,000 members of the public, this final act will be known as the “Cassini Grand Finale.”
“We chose a name for this mission phase that would reflect the exciting journey ahead while acknowledging that it’s a big finish for what has been a truly great show,” said Earl Maize, Cassini project manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
So we still have a couple of breathtaking years as Cassini slowly approaches its most intimate encounter with Saturn yet — returning unique photographs and historic science as it zooms through Saturn’s rings.