Extended Mission Discussion, What would you like to see? Options

[Jeff7]

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.

Oh I imagine it would be possible. Of course, making enough orbits around Saturn, combined with engine burns at the right times would probably take a generation or two.
And by that time, the ROTG's would have long gone too cold to make any useful amount of power.

[volcanopele]

I've heard nothing seriously discussed regarding anything more than what Bruce mentioned, simply continuing the tour for at least another 2 years. One of the initial goals I've heard discussed is to reduce the inclination of Cassini's orbit, since at the end of the nominal mission, Cassini is in a high orbit. the question has been whether to let the inclination drop naturally, or to use hydrazine to bring it back down faster. The fact that the natural inclination drop option seems to be favored suggests that mission planners are wanting to be conservative with the fuel left from the primary mission.

[Gilles]

My first time on this chat... It looks great and it is very interesting...

From previous experiences, we know that something will come up in x many years that will require the assistance of any hardware we would have in space (they are still measuring solar flares with Voyager !).

My feeling would be to try to get as much as possible in the main portion of the project and then find a nice, cozzy orbit to station Cassini (this doesn't mean Cassini will remain idle, but at least it would increase the "mile per gallon" ratio).

Soon enough, something will come up where Cassini will be a most unique and valuable asset (if it is still useable and has enough fuel).

In a nut shell, let's keep our options open.

[Redstone]

What is the feasiblity of passing through the Cassini division? Or the Encke gap? A periapsis lowering maneuver should make it technically possible, but I've no idea of the risk of impact when passing through the inner gaps in the rings. Failing that, a close flyby of Mimas (<1000 km) and the inner small moons would be something I'd like to see.

[Decepticon]

^^No Way!

Any risk is to much.

What is the feasiblity of passing through the Cassini division? Or the Encke gap? A periapsis lowering maneuver should make it technically possible, but I've no idea of the risk of impact when passing through the inner gaps in the rings. Failing that, a close flyby of Mimas (<1000 km) and the inner small moons would be something I'd like to see.

[tedstryk]

It is a shame the NASA brass didn't let Pioneer 11 fly inside the rings. This might be an option for very late in the mission, when the spacraft is about to die. Perhaps a course that takes it through the rings, and ultimately crashes into Saturn, sending data back all the way if it survives the ring plane passage.

[deglr6328]

It is a shame the NASA brass didn't let Pioneer 11 fly inside the rings.    This might be an option for very late in the mission, when the spacraft is about to die.  Perhaps a course that takes it through the rings, and ultimately crashes into Saturn, sending data back all the way if it survives the ring plane passage.

but....., didn't it?

[Guest_BruceMoomaw_*]

Nope -- Cassini flew through the ring plane twice in the gap between the F and G Rings. It DID come closer to Saturn than most of the rings -- but at the time it was just south (or was it north?) of their plane, and so got some very nice cross-sectional photos of them. It also got data on Saturn's fields and particles as good as Pioneer 11 could have gotten -- except that, unfortunately, there was a glitch in the magnetometer during that period that prevented it from getting direct magnetic measurements.

[Guest_BruceMoomaw_*]

Nope -- Cassini flew through the ring plane twice in the gap between the F and G Rings. It DID come closer to Saturn than most of the rings -- but at the time it was just south (or was it north?) of their plane, and so got some very nice cross-sectional photos of them. It also got data on Saturn's fields and particles as good as Pioneer 11 could have gotten -- except that, unfortunately, there was a glitch in the magnetometer during that period that prevented it from getting direct magnetic measurements.

I have no objection to the NASA brasss overriding the desires of Pioneer 11's scientists, though -- they decided it was more important to have it scout that same zone between the F and G Rings to see if it was safe for Voyager 2 to fly through it, which was the only way it could reach Uranus and Neptune. Had Pioneer been destroyed by dust during that passage, Voyager would have been reaimed to a second close flyby of Titan like Voyager 1.

[Decepticon]

Even if Pioneer did fly close to the rings, its imager was not the best for observing such small particles.

[tedstryk]

True, Pioneer didn't have imaging capability worth squat. But it had great particle and fields instruments. I think they should have risked it.

[ljk4-1]

NASA Considering Extending Cassini Mission Through 2010

By Jefferson Morris

12/27/2005 08:57:09 AM

NASA is considering a two-year extension to the Cassini mission that would extend the probe's exploration of Saturn and its moons through 2010.

"NASA has given us some additional funding to study what the options would be" for the extra two years, said Bob Mitchell, Cassini program manager at the Jet Propulsion Laboratory in Pasadena, Calif. "About a year from now, I'm expecting that NASA will give us an [answer] one way or the other."

http://www.aviationnow.com/avnow/news/chan...s/CASS12275.xml

[antoniseb]

NASA is considering a two-year extension to the Cassini mission that would extend the probe's exploration of Saturn and its moons through 2010.
http://www.aviationnow.com/avnow/news/chan...s/CASS12275.xml

Looking at the article, it says that Cassini might have enough hydrazene for a mission extension that doesn't involve a lot of fly-bys, but rather gives another two years or so of studying the rings (and perhaps Saturnian weather - my addition).

I suppose that would be a good thing to do... observe the rings as they move towards being edge on to the Sun. My gut feeling is that I'd really like to see a switch to Iapetus (from Titan) as the primary encounter target, but the low amount of fuel makes that unrealistic, and I suppose that there is really little that Cassini in particular can tell us more about that object's mysterious history.

[Cugel]

Looking at the article, it says that Cassini might have enough hydrazene for a mission extension that doesn't involve a lot of fly-bys, but rather gives another two years or so of studying the rings (and perhaps Saturnian weather - my addition).

That is not how I read it:

If we put together a tour that would look very much like what we're doing now - a Titan flyby every month or so and an icy satellite flyby stuck in here and there - then another two years would probably about run us out of fuel.

So we would get another 2 years of Titan flybys and some icy moons and after that... it's over. On the other hand, the 'uneventful' ring studying orbit could last much longer than 2 years, maybe even 10 years or so.

[tty]

That is not how I read it:
So we would get another 2 years of Titan flybys and some icy moons and after that... it's over. On the other hand, the 'uneventful' ring studying orbit could last much longer than 2 years, maybe even 10 years or so.

If NASA is willing to fund 10 more years of 'uneventful' research which I strongly doubt.

tty