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Juno at Jupiter, mission events as they unfold
Tom Tamlyn
post Mar 3 2017, 03:47 AM
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There are a dozen or more Juno abstracts attached to the program for the Juno sessions at the April EGU ("European Geosciences Union General Assembly") that Gerald linked to just upthread. However, none that I saw is longer than a page, some are only a few sentences, and some really don't contain any substance at all with respect to results.

None of this is surprising. As JRehling (and others) have noted, "Juno will not lend itself well to frequent science updates." There are plenty of good reasons not to release very preliminary figures on paper.

However, I noticed that the abstract for the JunoCam discussion had more meat to it than many of the others. I was also pleased to discover that the "professional" scientists have included Gerald as one of the JunoCam abstract's authors as an "independent scholar." It's fitting recognition for the amount of work and skill he has invested in working with JunoCam images.
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Gerald
post Mar 3 2017, 02:08 PM
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Thanks! I appreciate very much the allowance to collaborate with the Juno team, and the honor to be mentioned as a co-author. smile.gif
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tanjent
post Mar 30 2017, 03:57 AM
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At some point in the mission, after n successful orbital passes, and with enough science data already in the bag, Juno's management team will become less risk-averse and begin to consider taking a chance on re-lighting the main engine. The most obvious choice would simply be to make a delayed shift to 14-day orbits, as originally planned. But those unexpended resources might conceivably be used in other ways too. If the orbital science program were to be completed in the 54-day orbit configuration, what other innovative mission extensions could be considered? For instance, I'm wondering if it would be possible to approach Io or one of the small inner moons without being overcome by radiation. Or, since the probe is designed mainly for deep examination of the planet itself, could the orbit be adjusted to perform one or more close approaches over a pole or over the red spot, again without frying all the instruments?
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mcaplinger
post Mar 30 2017, 04:15 AM
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QUOTE (tanjent @ Mar 29 2017, 07:57 PM) *
At some point in the mission... Juno's management team will become less risk-averse and begin to consider taking a chance on re-lighting the main engine.

Not in the plan. https://www.nasa.gov/press-release/nasa-s-j...rbit-at-jupiter -- "NASA’s Juno mission to Jupiter, which has been in orbit around the gas giant since July 4, 2016, will remain in its current 53-day orbit for the remainder of the mission." (italics mine.)

Reducing the period simply shortens mission duration, it doesn't really change what science can be done.

The instrument suite is simply not capable of doing any substantive science of the moons, and the orbit is just fine as is for doing everything it can do. And I don't think the amount of remaining delta-v (about 350 m/s) is all that enabling of major orbit changes other than period reduction anyway. But feel free to peruse "Minimum impulse transfers to rotate the line of apsides" and report back -- https://trs.jpl.nasa.gov/handle/2014/37665 -- IIRC the rule of thumb is that the delta V of a apsides rotation is 1/4 of the velocity difference at the point where the old and new orbits cross.


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Disclaimer: This post is based on public information only. Any opinions are my own.
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