OPAG Reports, Formal proposals/evaluations of future outer SS missions |
OPAG Reports, Formal proposals/evaluations of future outer SS missions |
Nov 9 2007, 08:28 PM
Post
#1
|
|
Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
http://www.lpi.usra.edu/opag/announcements.html
That's one little URL with a lifetime's worth of reading material. Three detailed studies are available in PDF format. The missing body is Titan, which will be the subject of a forthcoming report. The three focus missions are: Europa Explorer: Fairly detailed description of a mission that is pretty much what Europa Orbiter would have been. Jupiter System Observer: Basically, Galileo 2 (without the antenna mishap!). The craft would start with a 3-year tour of all the Galileans, then spend 1 year in an elliptical Ganymede orbit, then the rest of the mission in a tight, polar Ganymede orbit (like MGS at Mars). That would map the heck out of Ganymede, but also be close enough to the rest of the system to make long-range observations for years. Note that Ganymede would thereby provide a lot of radiation shielding. Enceladus: where three profiles are examined in depth: Enceladus Orbiter only; Enceladus Orbiter with soft lander; Saturn orbiter with Enceladus soft lander. There's more to chew on here than I have had (or may ever have) time for, but I'll throw in my two cents' worth: Seems like a Europa-only mission would only benefit from coming after a JSO. EE would explore Europa much better than JSO would; why even have JSO observations at Europa if EE came first? In many ways, these two missions are competitive. EE would have the big payoff, but JSO seems like basic recon that would prime EE, especially giving specs on radar performance. But if we waited til JSO was 4 years into its mission before completing design of EE, then put EE sometime mid-century. If an Enceladus mission included a Saturn orbiter, then maybe the same orbiter could provide data relay for separate Titan elements. However, a lot of the Enceladus science goals would require an Enceladus orbiter, so I don't think a Saturn orbiter for Enceladus/Titan will win out. Note that Enceladus orbital velocity is low enough that the craft could manage to take lots of hits from ice pellets and survive. Put a bulletproof vest on the craft and let it soar through the plumes endlessly. |
|
|
Nov 14 2007, 08:07 PM
Post
#2
|
|
Senior Member Group: Moderator Posts: 3233 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
Yes, if the only difference were which moon was orbited, then yes, I would change my vote to the Europa Explorer. However, keep in mind that another thing that makes JSO interesting is that it can orbit Ganymede for a much longer period than EE could due to the greater radiation exposure at Europa. This provides a much longer opportunity to observe Io and Jupiter which maybe more important than the resolution gained by being at Europa (plus, with a much shorter mission at Europa, more than likely there were would be few if any observations of the rest of the system while in Europa orbit).
-------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
|
|
Nov 16 2007, 12:39 AM
Post
#3
|
|
Member Group: Members Posts: 706 Joined: 22-April 05 Member No.: 351 |
I've taken a look through the JSO and Europa Explorer proposals. My take on the choice for the next Flagship mission is that there are two classes of missions being proposed. The first class is to a single moon: Europa, Titan, or Enceladus. (While the Europa Explorer will do some Jovian system science, it's instruments are not optimized for that purpose.) The JSO mission would be a true Jovian system mission with a Ganymede mission in addition. It appears to this arm chair engineer that JSO could be flown to either Europa or Ganymede with fairly few changes.
In my opinion, if the next mission is a focused moon mission, Titan is the most interesting of these three options, and the proposed Titan mission with an orbiter, lander(s), and possibly a balloon (I read somewhere that this may be dropped from the proposal, but am not sure) seems very capable. However, if given a choice between a Jovian system mission that ends orbiting either Europa or Ganymede, I think this is the most science for the buck. -------------------- |
|
|
Lo-Fi Version | Time is now: 29th April 2024 - 09:01 AM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |