Thread by @mikamckinnon

"If Titan was orbiting the Sun instead of Saturn, we'd call it a planet." - Jim Green

"We must protect those bodies for future exploration." - Jim Green (Earth germs are nasty!)

"You gotta think about 80s technology millions of miles away." - Earl Maize

"We've got a main engine, & it's a great main engine. But we've got Titan, & it's a phenomenal main engine!" -Earl Maize on corse changes

"As it has time & time again, Cassini called in on-time & in perfect shape." -Maize

Cassini is such a reliable robot. It always calls home!

Starting tomorrow afternoon, Cassini will swap to realtime data transmission, talking to us every second it can for as long as it can.

"Cassini is not built for atmosphere. [...] We're a deep vacuum machine." -Maize

Cassini's tasted Titan & Saturn, but only lightly

"We won't watch Cassini burn up. We'll watch Cassini turn away from us, slowly losing radio signal." -Maize

...and then it'll vaporize.

Good robots never die. They just fade away, struggling to stay pointed at home to send us every last shred of data they can.

"We've been a bit ambivalent about when Cassini will lose signal." -Maize

That's because Saturn keeps surprising us. Yay new science!

Yeeeaaahhhh, that's a hurricane/aurora combo.

Linda Spilker describes the final photos as looking at favourite sites for Cassini's scrapbook. Dawww

"We'll be taking our clearest sample of Saturn's atmosphere." -Hunter Waite, on those final moments of data transmission

Final plunge data will help researchers figure out ring rain -- what material comes from the rings and what comes from Saturn's atmosphere?

"We'll be sad about the loss of a great machine ...but also proud. It's a bit corny, but 'Mission accomplished!'" -Maize

Awww, I was doing so good until Maize called Cassini a faithful traveler from Earth and thanked it. Now I realize I forgot my hankie.

"What we see & what we live with is that signal. When we see it is when it happens for us." -Maize
Times are signal-arrival, ignoring travel

Q: How's plutonium doing?
A: Our plan is to have a stockpile & not have that be a mission-limiting factor. -Green

Q: When will we get the final data?
A: Realtime downlink; post in ~20min. -Waite
"Understanding it may take longer." -Spilker

Cassini developed a technique for globally mapping via flybys "as though it were in orbit." Technique will be used again by Europa Clipper.

"The science isn't done until we share it." -Green

Cassini's mission will continue for years as we interpret the data.

"If there is a surface on Saturn, it would be hellishly hot. Cassini will vaporize long before reaching it." -Maize

Q: Can we prioritize listening for Cassini's heartbeat?
A: That's not worth surrendering the last sniffs of data. -Maize

Q: Will telescopes be able to watch?
A: Maybe but unlikely: Cassini's vaporizing flash will be on the day side. But please try! -Spilker

Q: Will rain in Australia wash out Cassini's final data?
A: No; so many contingencies & backups to make sure we get it somehow!

Q: What do you wish Cassini had?
A: Add better mass spectrometer! We didn't know about Enceladus geysers. -Spilker

A2: "I wouldn't change a damn thing." We went in with a Swiss Army knife of everything, & they've all been useful. -Maize

"Many of our models are too simple or just out & out wrong." Nothing makes a scientist happier than finding out model are wrong. -Spilker

Q: What will be the last piece of Cassini to survive?
A: Plutonium wrapped in iradium wrapped in aeroshells. Everything else will melt fast

"Our very last bit of science will be the radio signal fading away..."

I love Cassini will go down collecting data to the very end.

Q: What next for the scientists?
A: "Some of us will have paperwork to do." -Maize
At least 1 year of data processing.

Bwahahaha, Enceladus is approximately the size of Ireland.

Q: Would uncontrolled Cassini really hit a moon?
A: Need to keep odds under 1:1 million in 50 years.

"That means way outside of Saturn -- way, way outside of it -- or inside it." -Maize on why Cassini's final plunge is necessary