Cassini tickles Saturn's rings ahead of final death plunge

The Cassini space probe has begun a series of orbits designed to swing it through the edges of Saturn's ring system. The probe, which has been orbiting the gas giant since 2004, fired a six-second burst of its rocket motor at 0409 PT (1209 UTC) to put it into a swooping orbit 57,000 miles (91,000 kilometers) over the gas giant …

[Yet Another Anonymous coward]

The Audi option

>Cassini is travelling at thousands of miles per hour so should blast though the ring with minimal time for a collision.

The faster you drive, the less time for a collision and so the safer you are!

[Tom 64]

Re: The Audi option

But an impact at several thousand miles an hour could ruin your day, even an icecube at this speed could wreck the probe, or indeed, an audi.

I'll get my coat, going to work on an ice cube gun to use on audi drivers.

[DNTP]

You know what they say to do if you're about to hit a deer

Speed up!

[Professor Clifton Shallot]

Re: You know what they say to do if you're about to hit a deer

"The more you drive, the less intelligent you are."

Blimey, imagine if Fred Housego had had a desk job.

[bombastic bob]

Re: You know what they say to do if you're about to hit a deer

You say: "Oh, DEER!"

So far I have managed to 'swerve to avoid'. Stupid bucks jumping at you like it's a contest or something. One tried to race alongside of me after I swerved to avoid it. >60mph for a few seconds. I hadn't known they could sprint that fast. 'Prey animals' (vegetarian) just aren't that smart.

(yeah, has nothing to do with space probes like Cassini)

right before the video is lost, let's queue in some famous lines from Star Wars "the original"

"She's breaking up, she's breaking up!"

[allthecoolshortnamesweretaken]

Re: You know what they say to do if you're about to hit a deer

"You say Oh, DEER!"

That's the worst thing to call anybody.

[WraithCadmus]

Re: The Audi option

Ramming Speed!

[Winkypop]

Ladies and Gents of the Cassini project

Take a bow!

Excellent work.

[phuzz]

Re: Ladies and Gents of the Cassini project

One of these too >>>>>>>>>>>>>>>>>>>

[frank ly]

Does Uranus have rings?

Just idle curiosity.

[BinkyTheMagicPaperclip]

Re: Does Uranus have rings?

Yes, although it's angled at 90 degrees to every other planet.

Neptune has arcs instead of full rings.

[cray74]

Re: Does Uranus have rings?

Neptune has arcs instead of full rings.

Neptune has four full rings in addition to the arcs of the Adams ring.

[BinkyTheMagicPaperclip]

Re: Does Uranus have rings?

Whoops! Thanks for the update.

[Anonymous South African Coward]

Our neighbours on Saturn may object most strongly about us playing silly buggers with their rings.

Expect a small delegation to come over for a visit and some IDKFA...

[Pedigree-Pete]

IDKFA

..and perhaps an Earth shattering KBOOM! PP

[A Non e-mouse]

Interesting dilema

This outer ring isn't expected to give Cassini much of a problem, but the engine port has been covered just in case and its high-gain antenna is being used to shield as much of the instrumentation as possible

I'm glad I didn't have to make the choice between protecting the engine or the antenna!

[Benchops]

Re: Interesting dilema

> I'm glad I didn't have to make the choice between protecting the engine or the antenna!

To be fair, they'd already started detecting a fault in the AE-35 unit anyway.

[Patrician]

Re: Interesting dilema

Have one of these on me -------->

[Bill Gray]

Re: Interesting dilemma

As a guess here : small fleck of ice hits the parabolic dish used to focus signals to/from Cassini and makes a hole, say, a few centimeters across, and you just lose a bit of signal strength. The rest of the dish continues to work.

Make a hole that size elsewhere in Cassini, and you will not be going further into space today. Or at least, not with a fully functioning spacecraft.

Orbital speed for the F ring is about 16 km/s (rough mental calculation), or about twice that of objects in low-earth orbit. The speed of Cassini, relative to the ring particles, would be in roughly that ballpark (it's moving faster relative to Saturn, but in a different orbit plane and highly elliptical orbit). Double the speed means four times the kinetic energy.

[cray74]

Re: Interesting dilemma

As a guess here : small fleck of ice hits the parabolic dish used to focus signals to/from Cassini and makes a hole, say, a few centimeters across, and you just lose a bit of signal strength.

Yep. I worked on some materials issues for a portable military satellite radio that had an 2.5-meter parabolic dish (vs. Cassini's 4m dish). They put some ludicrously tight restrictions on what I could change for fear of weakening the signal, but the original design spec required tolerance of an entire petal (1 of 6) of the collapsible dish being shot away, which was a common event on the hilltops of Afghanistan. The radio also frequently oscillated several feet in a modest breeze and maintained its link.

Of course, talking to LEO commsats with a 2-kilowatt budget is a bit different than trying to listen to Earth with a few tens of watts. But a few holes in a 4-meter dish shouldn't deeply impact signal strength.

[Tom 7]

All the best science

ends in the fiery destruction of something.

[druck]

Re: All the best science

The point of the fiery destruction is that the probe doesn't crash in to and contaminate one of the major moons. But with all this diving in and out of the rings with a non trivial chance of collision, are the boffins sure that a debris cloud couldn't form that could eventually reach the moons?

[cray74]

1SWASP J140747.93-394542.6?

Isn't the artwork for that Mega-Saturn exo-planet?

[chasil]

Why destroy the spacecraft?

We just discovered that Saturn's great hexagon has turned green. Nobody has any idea why.

Dropping the probe into Saturn's atmosphere deprives us of any further ability to observe the poles at all.

This seems quite counterproductive.

[cray74]

Re: Why destroy the spacecraft?

This seems quite counterproductive.

Point taken, but it's running out of gas. The remaining options were "go into uninformative, long distance stable orbits that won't run the risk of contaminating collisions," or (ahem) "banzai! banzai! banzai!"

I'm a bit dubious of the contamination risk. Frankly, any germ on Cassini that has survived until now and might survive an impact on Titan or Enceladus is a superior lifeform that deserves the chance to thrive. (May it rule us benevolently.)

[Alistair]

on atmospheric insertion

During the first few moments Cassini descends through the atmosphere it sends back a ghostly whisper..

"My god, its full of stars!"

I for one will be listening in to that episode... (hope they broadcast ....)

Kudos for "rocket science" well done.