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.

[Guest_BruceMoomaw_*]

Looks like my whole idea was another pipe dream. I can't find anything on Juno's bit rate, even in Steve Matousek's otherwise excellent description ( http://trs-new.jpl.nasa.gov/dspace/bitstre...4/1/05-2760.pdf ), although an earlier strawman description of a similar mission had a 4000 bps rate. However, a drawing on page 4 of Matousek's report makes it clear that -- throughout its 32-orbit primary mission -- Juno can't possibly make a close flyby of Io (or Europa). And any extended mission will last no more than a month or so, since they want to make damn sure that the craft doesn't malfunction from radiation before they can steer it into Jupiter and thus make sure of missing Europa -- in fact, they may even end its mission after only about 16 orbits or so if they think they have enough data by then. They could, I suppose, maybe arrange a close flyby of Io if they had one hell of a lot of spare delta-V, but I can't see how they could have enough fuel margin left for that. (On the bright side, just by having a spectral resolution twice as good as Galileo's, the near-IR spectrometer on Juno could get a little more long-range compositional data on Io.)

[Stephen]

Looks like my whole idea was another pipe dream. I can't find anything on Juno's bit rate, even in Steve Matousek's otherwise excellent description ( http://trs-new.jpl.nasa.gov/dspace/bitstre...4/1/05-2760.pdf ), although an earlier strawman description of a similar mission had a 4000 bps rate.

That document alludes (p8) to the spacecraft using the Ka band (albeit: "For the GS measurements, Ka-up and downlink is only available from the DSN station Deep Space Station (DSS)-25 at Goldstone, California").

What bit rate would be expected from a Ka band link between Jupiter & Earth?

EDIT: I think I may have found the info to that last query in this PDF document, albeit maybe not specifically for Juno. Check out:

http://hrdd.grc.nasa.gov/resources/Pdfs/Outerplanetary.pdf

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Stephen