Third Response to Galilean Satellite Observer

Ted Stryk e-mailed me his thoughts on a Galilean Satellite Observer, which I reprint with his permission. This follows comments from John R. and Bruce Moomaw to my original posts at http://futureplanets.blogspot.com/2009/08/basis-for-galilean-satellite-observer.html and http://futureplanets.blogspot.com/2009/08/galilean-satellite-observer.html.

I think GSO would be an excellent idea if JEO is to costly. Galileo, while it made fascinating discoveries, was horribly crippled by its antenna troubles. Not only is the data coverage thin, but because the data returned was so selectively targeted, the chances at serendipitous discovery were greatly reduced. Having followed the Cassini orbital tour, it is now even more painfully obvious what we missed. In addition to much more complete multispectral mapping of the four Galileans and Io monitoring (and searching for plumes on Europa, this spacecraft would be well equip to send back the atmospheric movies of Jupiter that Galileo could not. Plus, it could do the initial sounding of Europa to determine the thickness of the ice.

Granted, JEO has its Galileo-like tour, but the mission has a very finite end - it can't last too long in Europa orbit. GSO may well last as long as or longer than Galileo. Yes, there will be major sacrifice at Europa, but while I find Europa interesting, I fail to see why it it is so much more interesting than Io and even Ganymede. The four Galileans compose a system, and I don't think we have reached a point where we should focus so heavily on just one member.

I will admit that there is another thing infecting my thoughts. I would really like to see some more extensive studies of Io, and GSO might well return as Galileo did late in its mission for some more in-depth studies. There is no expanding JEO's tour. If a Discovery (with the Stirling RTG) proposal like the Io Volcanic Observer is chosen, my views on GSO would change considerably.