[X] My Assistant

[Guest_BruceMoomaw_*]

http://www.nasa.gov/home/hqnews/2005/jun/H...rontiers_2.html

Yeah, I know it ain't Saturn, but we don't seem to have any proper slot for Jovian news -- including yesterday's totally unexpected announcement that Amalthea's density is so low as to suggest that it's a highly porous ice object; maybe a captured Kuiper Belt Object reduced to rubble by infalling meteoroids. As Jason Perry says, this might explain those previously mysterious light-colored patches on Amalthea -- they may be its underlying ice, exposed by impacts that punched through the layer of sulfur spray-painted onto it by Io.

Scott Bolton has been pretty talkative to me already about the design of Juno. It certainly won't be as good in the PR department as Galileo or Cassini, but it DOES carry a camera -- as much for PR as for Jovian cloud science, according to Bolton. And since the latitude of periapsis of its highly elliptical orbit will change radically during the primary mission, I wonder if they might be able to set up at least one close photographic flyby of Io and/or Amalthea? (I believe, by the way, that this selection is a bit ahead of schedule -- and it certainly indicates that NASA's science program under Griffin won't be a complete slave to Bush's Moon-Mars initiative.)

[Guest_BruceMoomaw_*]

It's a possibility -- but I suspect you're talking about something that would still hit the NH cost band (which may be why Volcan was rejected). One other Io Discovery mission was proposed: William Smythe's "Firebird" -- a solar-powered craft which would make just a single flyby of Io, but would take thousands of photos at extremely high speed during that one flyby, plus a comparable number of near-IR mineral maps and IR thermal maps, and release two little subprobes to make very low-altitude flights through volcanic plumes carrying mass spectrometers. It would then play back its huge store of recorded data at liesure over several months after its Jupiter flyby. This, of course, would lack any ability to observe changes on Io -- as well as covering much less of its surface -- but it would also cost a lot less. It was rejected, too; but in this case we really are talking about something with a good chance of hitting the Discovery cost band if properly adjusted.

This, of course, raises another, cheaper possibility -- the fact that any craft that makes a Jupiter gravity-assist flyby en route to a more distant destination will also have a chance at one close Io flyby. New Horizons could have made one if that idiot Goldin hadn't delayed it from Nov. 2003 to Jan. 2006 for no reason -- in fact, during the 1990s, when the Pluto Express flyby was being planned for that launch window, Germany expressed interest in adding an Io volcanic-plume probe with a mass spectrometer itself.

In any case, the white paper on Io missions presented to the Decadal Survey -- which is pretty much the latest thinking on the subject -- can be found at http://www.lpi.usra.edu/opag/io.pdf .