[X] My Assistant

[Decepticon]

I'm already looking forward to the extended mission. And one target I hope gets a closer look at is Iapetus.

(And yes I understand money and fuel are issues when it comes to this.)


Close Ups of the that ridge would be very interesting. Along with some Radar Observations.

Another reason is to get as much mapping done on all the major moons.




What would you like to see in the extended mission?

[Jeff7]

Probably just a continuation of the primary mission - that's likely all we'd get anyway. We can't go visit another planet, like Voyager did, unless something came along and strapped a booster rocket on. Maybe they'll do some closer, riskier flybys of the moons as Cassini's death seems imminent.

[djellison]

Cunning flybys and aerobraking into titanian orbit for me please

Doug

[cIclops]

What would you like to see in the extended mission?

A fully functioning spacecraft and some images of the ring particles.

[Gsnorgathon]

Well, here's the trick: "More of the same" would be great, and allow for a longer extended mission without damage to the spacecraft.

But there are some nifty things I'd like to see that are potentially hazardous, like closer imaging of Enceladus or the rings. I'd love to see meter-scale images of Enceladus, and it would be fabulous if Cassini could get close enough to the rings to resolve individual ring particles (where "particles" would presumably mean mean objects meters in diameter).

Orbiting Titan for more radar mapping would be fine with me, but is it even possible?

[Decepticon]

Orbiting Titan for more radar mapping would be fine with me, but is it even possible?

I've seen topics about this on space.com and the argument was both ways. It looked more like "I'm Right Your Wrong" Thread.

I remembered reading before Orbit Insertion on the cassini web page that it was possible.

[cIclops]

... another close look at Phoebe, is it a Kuiper belt object or not? and what are those "unidentified minerals"?

... and a really close flyby of Enceladus to sample some of that atmosphere with INMS

[Jeff7]

Well, here's the trick: "More of the same" would be great, and allow for a longer extended mission without damage to the spacecraft.

But there are some nifty things I'd like to see that are potentially hazardous, like closer imaging of Enceladus or the rings. I'd love to see meter-scale images of Enceladus, and it would be fabulous if Cassini could get close enough to the rings to resolve individual ring particles (where "particles" would presumably mean mean objects meters in diameter).

Orbiting Titan for more radar mapping would be fine with me, but is it even possible?

I have my doubts that Cassini would be able to image anything that close and small. But then, I don't have any good technical data on the focal length of the narrow angle camera onboard Cassini.

[Phil Stooke]

I understand that Cassini is not sterilized to a high degree, and would probably not be put into Titan orbit for planetary protection reasons. If they are close enough in for extensive radar mapping there is a lot of drag from the atmosphere, so the orbit would decay fairly quickly, certainly long before we could have thoroughly characterized the organic chemistry with future missions. But lots more close passes (preferably with lots of additional radar coverage) plus other moon flybys should be easy to do.

Phil

[paxdan]

I'd love to see meter-scale images of Enceladus, and it would be fabulous if Cassini could get close enough to the rings to resolve individual ring particles (where "particles" would presumably mean mean objects meters in diameter).

The closest images of the rings during the primary mission has already occured, it was during orbital insertion. How close were they to resolving individual ring particles? The images in question that potentially show some fine structure are here, here and here. I have a printout of the last image of the bending and density wave by my desk at work. Yeah, I would love to see some more ultra close-ups of the rings during the extended mission.

I can't remember where i read it, but i read that an option at then end of the mission was to raise cassini into a high orbit, and keep it active on a minimal program for decades. How long could the extended mission be, are we talking 20-30-40 years?

Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favour fire.
But if it had to perish twice,
I think I know enough of hate
To say that for destruction ice
Is also great
And would suffice.

Robert Frost

So at the end of the extended mission do you want Fire (a glorious death, either in saturn or titans atmosphere, or a ring plane impact) or Ice, a long cold extended orbit till cassini goes cold.

[Jeff7]

I figure they'd probably sooner plunge Cassini into Saturn rather than Titan, like they did with Galileo. A ring plane impact would just dent the hell out of Cassini, but not really destroy it outright - unless they sent it in in a retrograde orbit.


Anyone know how much fuel is left in the main booster? Does that still get used for orbital adjustments, or does it rely solely on smaller thrusters for that?

[Guest_BruceMoomaw_*]

Cassini manager Bob Mitchell has just informed me that the chance of aerobraking it into orbit around Titan is zilch: "With regard to aerocapture at Titan, I think it's a very safe bet to say that that isn't going to happen. I guess I wouldn't go so far as to say it's impossible, although I think it probably is, but since our speed relative to Titan is around 6 - 7 km/sec, it would take so many aerobraking passes to get captured that it just isn't a practical thing to consider."

Beyond that, he says the nature of an extended mission is (as I would suspect) completely up in the air: "There hasn't been any narrowing of the possibilities for an extended mission. Various of the scientists are forming their own opinions and
priorities, but as a group, nothing has been done."

I will add myself that some of the highest-priority things we want to do can be done from the relatively low-altitude polar orbit that Cassini will be in at the end of its primary tour -- both more protracted ring observations and adjustments of the periapsis to allow more close flybys of moons from Janus at least out to Hyperion, if we choose. The main problem with this is that Cassini would keep flying past the same side of Titan -- if we want really widespread surface coverage of Titan (which I take for granted we DO want at this point), we'll have to either keep adjusting the azimuth of the polar orbit or switch Cassini back to a low-inclination orbit.

[PaleBlueDot]

if i rember correctly, i read a while back on cassini webpage that some other options for the extended mission could include a trip back to jupiter or uranus via multiple titan assists

[Marcel]

if i rember correctly, i read a while back on cassini webpage that some other options for the extended mission could include a trip back to jupiter or uranus via multiple titan assists

That's exactly what i was thinking. Uranus would be my choice. But how can one escape from the saturnian system and later on brake in UOI with so little fuel left (how much is left actually ?) I bet a gravity assist from titan might help, but completely leave saturn needs a lot of fuel i'd say.

[Bjorn Jonsson]

Escaping Saturn for a later planetary flyby isn't possible. If Cassini could escape Saturn orbit it would end up in an orbit similar to Saturn's.