Is Europa really the "highest priority" of the community?, Cleave said it was at LPSC? Options

[mcaplinger]

From Emily's LPSC blog: "Bob Pappalardo would not sit down until he got Cleave to acknowledge that Europa is the consensus highest priority of the planetary science community."

Cleave was obviously poorly prepared for this session, but I don't see that this acknowledgement is either meaningful or particularly accurate. If Europa were the "highest priority" of the PS community as a whole, then one might wonder why we were spending all this money on Mars. I could easily imagine that Europa is the highest priority of the outer planets community, but frankly I was surprised when Europa Orbiter appeared in the '07 budget (presumably the result of some serious lobbying on someone's part.) It was pretty obvious to me then that there would be no money for it, especially in the aftermath of JPL running the old EO project into the ground with cost overruns and engineering upscopes. (And JIMO is best forgotten.)

Don't get me wrong, I would love to be involved with a Europa mission (we did what I think was a good proposal design for EO) but I don't see either the money or the political support being there in the near term. I know it's frustrating, but one has to be realistic, and it might help to avoid the aura of entitlement that I perceive is building in some parts of the community (not referring to you, Bob). Of course, I am just a lowly engineer.

[elakdawalla]

That was slightly sloppy reporting on my part, and I need to go back to my [illegal] recording to try to see exactly what Bob said. It generally appears that Mars is considered wholly separately from exploring the rest of the solar system (I am kind of curious how the financial priorities are set between the Mars program and everything else; I don't know anything at all about that).

Leaving out Mars, the Decadal Survey identified priorities for missions to other targets in the solar system, identifying one large class mission (assumed rate one per decade) and five medium class missions (assumed rate three per decade, with two extras listed) as being the top priorities of the science community. Europa stands alone in that large mission class. The five medium missions are, in order: Pluto/KB Explorer; lunar South Pole/Aitken Basin sample return; Jupiter Polar Orbiter with Probes; Venus In-Situ Explorer; and Comet Surface Sample Return.

One reason Bob wanted to stand up and say that yesterday is because he (and the rest of the Europa community) were alarmed by the possibility that Jonathan Lunine's provocative suggestions of Titan as being the one target he would explore if forced to choose one would be seen as "mixed messages" coming out of the outer planets community. Lunine's point is debatable, but as far as mission planning is concerned it's not really a relevant one. Planning out future missions requires not only looking at what questions scientists desire to answer but also the maturity of the field and the technological readiness to start a new mission. With Cassini still at Saturn it's not time yet to start a Titan mission now -- one would guess it would be a top candidate for the single large mission of the next decade, after Europa.

Doesn't look like NASA's too interested in considering large missions at all right now though.

--Emily

[Guest_AlexBlackwell_*]

Planning out future missions requires not only looking at what questions scientists desire to answer but also the maturity of the field and the technological readiness to start a new mission. With Cassini still at Saturn it's not time yet to start a Titan mission now -- one would guess it would be a top candidate for the single large mission of the next decade, after Europa.

But what if "the maturity of the field and the technological readiness," not to mention the funding, is not in the cards for the strawman Europa mission recommended by the Decadal Survey as the next Flagship-class mission? Do we have to wait to punch the ticket of these prioritized mission sets when, for example, other new targets may emerge during the interim? The problem with Decadal Surveys (or all long-term "roadmaps") is that they're usually not too discovery-driven. Of course, the hurdles (programmatic and technological) facing outer planetary exploration are much different than those facing Mars exploration, but I wonder whether a prioritization scheme similar to the Pathways/Next Decade approach used for Mars might be useful for the outer planets.

Doesn't look like NASA's too interested in considering large missions at all right now though.

True, which may make all of this debate moot.