[X] My Assistant

[Toma B]

26 Nov. Close Flyby (500 km.) of Rhea...(Size: 1538 km.)
27 Nov. Distant Flyby (108,000 km.) of Enceladus...(Size: 512 x 494 x 490 km.)
27 Nov. Distant Flyby (86,000 km.) of Helene...(Size: 36 x 32 x 30 km.)

This should be interesting...

Can anybody give a bit more information on the upcoming flybys???

Is this the best image of Helene that we have???
Vojager 2 - distance :341000 km)

[Mariner9]

400 Meters Per Pixel..... be still my beating heart.

OK, OK.... we know that they don't put in the highest res picture footprints on these diagrams.

Still..... one of the only things about Cassini that I find disappointing is the pointing problems they have due to the scan platform being removed and the resulting need to turn the spacecraft all the time to share the wealth with the various instruments. Sheesh... we got more high res pics of Europa on a Galileo flyby than we seem to get from the Enceladus flyby on Cassini.


But the more I think of it... that may not be "one of the only things" I find disappointing about Cassini... it might be the only thing.

I'll stop griping now.

[ugordan]

Sheesh... we got more high res pics of Europa on a Galileo flyby than we seem to get from the Enceladus flyby on Cassini.
But the more I think of it... that may not be "one of the only things"  I find disappointing about Cassini...  it might be the only thing. 

You have to realize that at the time the only Enceladus highest-res image was being taken, another instrument (UVIS) was performing a stellar occultation and it controlled pointing. Even if you had Galileo and its scan platform, the optical sensing instruments would still conceivably be pointed at the same direction, preventing both stellar occultations and nadir imaging.
The other biggest problem, as tedstryk already elaborately pointed out is the readout time of the ISS camera. It's typically around one minute and the absolute minimum is around 6 seconds, IIRC. Worse still, the readout time "windows" are predefined meaning you need to select the next greater provided time interval before taking the next image, otherwise you end up with an image that's truncated on the bottom.

Concerning this, even a 6 second delay in readout during Rhea closest approach and with a speed of 7 km/s means that not only there will be NO image footprint overlapping for the NAC, there will also not be any overlap between WAC frames. It's quite possible that, due to bad timing, the cameras will miss the bright rayed crater.
Keeping my fingers crossed, but aren't holding my breath...