Printable Version of Topic
Click here to view this topic in its original format
Unmanned Spaceflight.com _ Cassini general discussion and science results _ Tb Icy Satellite Flybys
Posted by: Bjorn Jonsson Nov 26 2004, 10:28 PM
In mid-December Cassini will fly by Dione at a distance of 81,000 km. I did a few quick renders showing the viewing geometry:
http://www.mmedia.is/bjj/misc/css_stuff/dione_20041214_2300.jpg
http://www.mmedia.is/bjj/misc/css_stuff/dione_20041215_0130.jpg
http://www.mmedia.is/bjj/misc/css_stuff/dione_20041215_0430.jpg
These have a field of view (FOV) three times bigger than Cassini's NAC. This should yield some great coverage of areas poorly seen by Voyager (in fact these images will be much better than the best images obtained by either Voyager of any of Saturn's icy satellites).
Also Cassini will fly by Mimas at a distance of 114,000 km but I don't know if it will take any images. This rendering has a FOV identical to Cassini's NAC and shows Mimas near the time of closest approach:
http://www.mmedia.is/bjj/misc/css_stuff/mimas_20041215_0500.jpg
Also there is a 240,000 km Rhea flyby but I also don't know if Rhea will be imaged. Jason ? ;-)
Posted by: tedstryk Nov 26 2004, 11:01 PM
I wish the Cassini folks would make a list of all the orbits with highlights and closest approaches like the Galileo team did for Galileo during the primary mission. Is anything like that in the works?
Posted by: BruceMoomaw Nov 27 2004, 01:07 AM
There's a very detailed schedule of exactly that (running 13 pages) in the Oct. 2003 Cassini Operations Plan, of which I have a copy. If anyone wants to know anything specific about either targeted and untargeted moon encounters or other aspects of the 4-year tour (including ring-edge approaches, other orbital characteristics, and the planned times for all orbital trim maneuvers), let me know and I'll look it up for you. It lists, I believe, all moon encounters within less than 100,000 km.
Posted by: Decepticon Nov 27 2004, 02:15 AM
^^^ I would love to see that!!!!
Anything showing what cassini will see with each orbit.
Posted by: AlexBlackwell Nov 27 2004, 03:41 AM
If you're referring to the Cassini Mission Plan Revision O (October 2003), then be advised that the tour reference trajectory has undergone several updates since then. That said, a lot of the values are unchanged, especially late in the tour, but there are some differences. For example, a couple of days ago Cassini Mission Planning (MP) gave a new recommendation for the C/A altitude during the T5/T7 passes.
Posted by: M_Welander Nov 27 2004, 12:03 PM
I've written a couple of small programs that take SPICE kernels (so you can update the data once kernels that consider new trajectories are released) and display the current view from the spacecraft and calculate encounters.
They're really just written for my own personal use, and I can't promise they're actually entirely correct, but since there seem to be some interest here in such things, I could perhaps clean them up and release them. If anyone's interested?
Oh, and by the way, hi people! This is my first post here, though I joined a while ago once I realized a long time hero of mine (Björn Jónsson) frequented the board - meaning this is serious stuff.
Posted by: Decepticon Nov 27 2004, 03:03 PM
Great site to compare Cassini data with Voyager data.
http://www.ssc.uwo.ca/geography/spacemap/contents.htm
I had no clue home many images where taken buy Voyager. I was very surpised with this link.
Posted by: volcanopele Nov 27 2004, 06:23 PM
No Mimas or Rhea observations as far as know. planned for orbit 0B There are global and regional observations planned for Dione on late Dec. 14 and very early Dec. 15 UTC.
Posted by: Bjorn Jonsson Nov 27 2004, 11:17 PM
They're really just written for my own personal use, and I can't promise they're actually entirely correct, but since there seem to be some interest here in such things, I could perhaps clean them up and release them. If anyone's interested?
I for one would be interested - I've been messing with SPICE kernels and SPICELIB with great results but it isn't exactly the easiest thing in the world.
Posted by: Sunspot Nov 27 2004, 11:23 PM
How many potential observing opportunities were lost after the scan platform was dropped from the space craft design?
Posted by: djellison Nov 28 2004, 12:52 AM
More than enough to make anyone interested in the mission to go "damnit"
Doug
Posted by: Decepticon Nov 28 2004, 12:58 AM
^ That is Sad 
Posted by: M_Welander Nov 28 2004, 01:02 AM
All right, then. I've tried to set up an FTP here with it for you people to download - let's hope it works (and scream if it doesn't). The information for it is as follows:
ftp://ftp.cybercraft.no-ip.com
Username: Tools
Password: tools
If possible, use a real FTP client program (that is, not Internet Explorer).
Posted by: Decepticon Nov 28 2004, 04:04 AM
^ Thanks!
Posted by: M_Welander Nov 28 2004, 08:22 PM
I'm noticing that some people appear to have read my post too quickly. Please note that it is the username that is "Tools" and the password that is "tools", and not the other way around.
Other than that, it seems to be working. Oh, and the FTP server will not be available forever, to avoid unauthorized access. But once it's down, you can always ask me for the files, should you read this thread too late.
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)