OPAG Spring Meeting Presentations

Well, Hey Hey all! You've probably been wondering where in the world I have been. Well, I have been around, but unfortunately there hasn't been much news lately, and I've been spending my free time playing Europa Universalis III rather than processing Io images. Sorry, but it is true. I think it was time well spent. I just conquered Constantinople. I feel rather proud of myself. So I haven't abandoned you all. I will try to post more often. I'm sure there are scraps of news I've missed.

Anyways, the presentations from the OPAG Spring Meeting are finally online. Yes, Hell has frozen over. Or maybe that was Europa. Wait, that's redundant, scratch that... I kid, I kid. NASA's Outer Planets Assessment Group (OPAG) held their spring meeting in Bethesda, Maryland last month and we have been waiting for the presentations to get posted online. Not just me, but Van over at Future Planetary Exploration has been waiting.

Two presentations caught my eye. The first is by my advisor, Alfred McEwen, and covers the Io Volcano Observer. This presentation covers much of the same terrain that we saw in the presentation given in December at the Io Workshop, but it also goes into further details over a possible tour plan and the science goals. The example tour presented includes some info about how the IVO team might plan the mission. The sample tour includes no flybys with altitudes less than 291 km in altitude, but the previous slides does point out that the do plan to try closer encounters, down to 100 km, later in the nominal mission and extended mission. Closer encounters are particularly important in order to observe small scale features on the surface (like skylights) and to use the mass spectrometer within an active plume. The sample mission assumes a different launch from the nominal January 2015 one, so again, take the sample tour with a grain of salt. Still, it would seem that the tour designers want to keep the sunlit region on Io during the flybys fairly similar, but not so similar that only half the surface would ever be visible during these encounters.

The IVO presentation also concentrates on the science objectives for the mission. These mission objectives largely cover those proposed for the Io Observer mission type available for the New Frontiers-3 announcement of opportunity (but all but impossible because NF-3 can't use radioisotope power sources). These science goals include (level 1 goals in bold):

• Understanding the eruption mechanisms for Io's lavas and plumes and how these compare to similar processes on Earth and other terrestrial planets
• Determining Io's interior structure, particularly the melt fraction of the mantle
• Determining the properties and mechanisms of Io's tidal heating and implications for the orbital evolution of Io and Europa
• Investigating the processes that form Io's mountains and other tectonic structures in the satellite's high heat flow environment
• Understanding Io's atmosphere and ionosphere and their connection to Io's volcanism
• Determining whether Io has a magnetic field
• Understanding Io's surface chemistry, including volatiles and silicates
• Improving our understanding of Jupiter system science

The IVO team feels that this mission along with the Jupiter Europa Mission, would go along way toward responding toward these goals, though many require a high data rate as a result of the fast encounters, so a large amount of data storage will be needed (~20 Gb) in order to capture all the close approach data, particularly from INMS and RCam. McEwen also stresses the synergy between JEO and IVO, making it clear that even with the Europa/Jupiter System Mission having been selected, the Io Volcano Observer will still be needed by the Io community, as it provides much more information about the polar regions, particuarly the heat flow up there, and would provide much more data on the composition of Io's lavas. Finally, IVO would help to mitigate EJSM's risk by testing the ASRG, the next generation of radioisotope power source to be used by IVO, if EJSM uses them as well.

Curt Niebur gave a presentation on the results of the Outer Planets Flagship Mission selection process. Niebur goes into detail the rationale behind the Selection Panel's decision to give higher priority to the Europa/Jupiter System mission for the next decade flagship mission. Basically, as has already been reported, the EJSM concept was seen as been more technically mature, the result of several prior mission studies over the last decade for a Europa follow-on mission to Galileo. Niebur notes several issues with the Titan concept, but the technical review basically noted that technical issues and design drivers many of the mission elements, such as the SEP stage development, the thermal subsystem, the integration of the in situ elements, and aerobreaking where not realistically reflected in the budget estimate.

Link: OPAG Spring Meeting Presentations [www.lpi.usra.edu]