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Juno development, launch, and cruise, Including Earth flyby imaging Oct 9 2013
PhilHorzempa
post Apr 3 2006, 09:57 PM
Post #1


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I thought that it was time to start a new thread devoted to the JUNO Jupiter
Orbiter mission. This New Frontiers Mission #2 seems to be a "stealth" project
with little information available on the Web. In fact, the official NASA JUNO
web site is quite pitiful. It contains the minimal amount of information on what
seems to be an intriguing mission, in terms of both science and engineering.

Does the UMSF community have information on this mission that has not
been widely seen before?

Another Phil
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Guest_BruceMoomaw_*
post Apr 10 2006, 03:05 AM
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OK, here are those crumbs. The JPL description is pretty good, but there are a few things missing from it:

(1) The 2002 Solar System Decadal Survey noted that the five main goals for the next Jupiter mission are: (A) Determine if Jupiter has a central core to constrain models of its formation; ( B ) determine the planetary water abundance; ( C ) determine if the winds persist into Jupiter's interior or are confined to the weather layer; (D) assess the structure of Jupiter's magnetic field to learn how the internal dynamo works; and (E) measure the polar magnetosphere to understand its rotation and relation to the aurora. Juno will do a nice job on all five - and while, the Survey's original desire for at least one and preferably 2 or 3 deep entry probes (down to 100 bars) would have further improved the data on ( B ) and ( C ), the added expense was so great that a deep Jovian Multiprobe Flyby mission by itself is now ranked pretty low on the list of desired New Horizons missions -- shallow Galileo-type entry probes of the other giant planets are higher-ranked. Moreover, the data from Juno will allow us to better plan the targeting of those deep Jupiter entry probes when we finally DO fly them. (Note also that -- if they absolutely have to descope Juno -- they could toss off every single instrument except the microwave radiometer and magnetometer, and lose only goal (E) in the process.)

(2) Currently we know Jupiter's gravity-field harmonics down to level 6 -- Juno will take it down to level 12 to 14. Not only can it nail down the size of any hevy-element core -- which is crucial to decide which of the two rival theories of giant-planet formation is true -- but it can measure that core's rotation rate, and even obtain profiles of the density of the planet's middle layers sensitive enough to determine how deep its convective wind cycles really run, all the way down 1/5 of the way to the core!

(3) Our current knowledge of Jupiter's magnetic-field harmonics is level 4. Juno will take it all the way down to level 20 -- much BETTER than we can ever obtain for Earth itself, where we're forever limited to level 14 due to interference from crustal fields! Thus Juno is likely to provide radical new information not only on the generative processes of Jupiter's magnetic field (including the dynamo radius and changes with time), but of Earth's field as well.

(4) Knowledge of the total oxygen content of Jupiter's atmosphere is crucial -- and the Galileo entry proe didn't get it because of its bad-luck fall (9-1 odds against) into a hot spot where a downdraft removed the local water vapor. The probe DID find not only that the concentration of the other heavier elements -- Ar, Kr, Xe, C, N and S -- was somewhat lower than expected, but that they were very consistent in being enriched about threefold relative to the Sun, whereas much bigger element-to-element differences had been expected in that ratio. This was a shock. The logical conclusion is that the icy planetesimals that formed Jupiter were actually made of much colder ice than that which existed at the planet's current distance from the Sun (150 K) -- those other elements were imprisoned either in regular ice at only 20-30 deg K or clathrates at >38 K, so either the planet itself formed much farther from the Sun and migrated a great distance inwards, or the planetesimals that formed it themselves came from much farther out and migrated inwards before accreting to form Jupiter at something like its present distance from the Sun. (The entry probe found further confirmation of this in the nitrogen isotopic ratios, which indicates that Jupiter's nitrogen was originally delivered as molecular N rather than as ammonia -- which in turn provides an odd clash that I've mentioned elsewhere with the indications from Huygens that Titan's nitrogen DID arrive as ammonia in relatively warm ice.)

Since water ice was the carrier of all these other heavier elements, we need to know the ratio of water ice to them -- for which we must know Jupiter's current oxygen content. If the planet's oxygen is enriched to only about the same degree relative to the Sun as all the other heavier elements measured by the Galileo entry probe, then they must have been carried into the planet in very cold water ice, from the Kuiper Belt or beyond -- and Jupiter itself may have originally accreted at that distance and then spiralled a great distance inwards. But if oxygen turns out to be enriched more relative to its solar abundance than those other elements -- say, about 9 times solar abundance -- then those other elements were trapped by water ice, and carried into the forming Jupiter, in a more diluted form as clathrate ices, which could have formed somewhat closer to the Sun.

The microwave radiometer (whose viewfield is 1 degree at the equator and 4 degrees at the poles) should allow water abundance measurements down to about 100 bars -- plus better ammonia data (which is a bit fuzzier from the Galileo probe than we would like), thus nailing down both Jupiter's overall oxygen content, and further sharpen our data on its nitrogen content. It will also get more data on the temperature and cloud depth profiles in different parts of the planet, which in turn should help tell us more about just how deep the convective and wind patterns that create the belt-zone structures really run. But it can only do all this reliably because the Galileo entry probe measured the other trace components of Jupiter's atmosphere -- some of which, like PH3, have a significant effect on the planet's microwave spectrum.

(5) Juno's mission is scheduled to run 32 orbits of 11 days each -- and any extended mission will be only a month or so, because they want to make sure that they can crash it into Jupiter, and thus avoid any chance of contaminating Europa, before they lose control of it from radiation damage. In fact, they may end the mission ahead of time -- most of its science will come from its first 16 orbits, and its periapsis latitudes are designed to give it only 5% of its total radiation dosage during that period. (As the JPL paper says, 5 of its first 7 orbits are directed toward microwave radiometry, with all the rest of its orbits being devoted to precision tracking for gravity-field data.)

(6) Juno spins at 3 rpm. Its "JunoCam" -- the most dispensable of all its instruments, whose data will be processed by students at JPL -- should send back 5-10 images per orbit. Juno is focused entirely on the planet itself -- any data it does get on the moons will be pure gravy. For instance, it's very unlikely that they will be able to arrange for it to fly through Io's flux tube.
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- PhilHorzempa   Juno development, launch, and cruise   Apr 3 2006, 09:57 PM
- - jamescanvin   Up to now we've been using the "Nasa Pic...   Apr 4 2006, 01:19 AM
|- - Sunspot   QUOTE (jamescanvin @ Apr 4 2006, 02:19 AM...   Apr 4 2006, 01:55 PM
- - Decepticon   Will this probe make any attempt to image Jupiter...   Apr 4 2006, 12:16 PM
- - Analyst   Try this. Analyst   Apr 4 2006, 02:53 PM
|- - Sunspot   QUOTE (Analyst @ Apr 4 2006, 03:53 PM) Tr...   Apr 4 2006, 03:12 PM
- - lyford   I think the link got munged in the quote. Correct...   Apr 4 2006, 03:17 PM
|- - Sunspot   QUOTE (lyford @ Apr 4 2006, 04:17 PM) I t...   Apr 4 2006, 06:05 PM
|- - Bricktop   QUOTE (Sunspot @ Apr 4 2006, 08:05 PM) Sa...   Apr 10 2006, 10:29 AM
- - Harder   Keep on trying! This pdf doc is a good read. I...   Apr 4 2006, 06:39 PM
- - BruceMoomaw   Or just turn to that address for the overall JPL T...   Apr 4 2006, 06:59 PM
- - BruceMoomaw   OK, here are those crumbs. The JPL description is...   Apr 10 2006, 03:05 AM
- - Mariner9   Using solar power for JUNO has always intrigued m...   Apr 11 2006, 12:36 AM
|- - BruceMoomaw   QUOTE (Mariner9 @ Apr 11 2006, 12:36 AM) ...   Apr 11 2006, 02:18 AM
|- - helvick   QUOTE (BruceMoomaw @ Apr 11 2006, 02:18 A...   Apr 11 2006, 06:34 AM
- - Bart   I was rooting around on the ADS server, looking fo...   Apr 11 2006, 01:09 AM
- - edstrick   One thing's for sure... the increase in solar ...   Apr 11 2006, 09:29 AM
- - edstrick   "It describes an instrument for Juno......   Apr 11 2006, 09:43 AM
- - BruceMoomaw   Slight historical correction: NASA decided to add ...   Apr 15 2006, 01:48 AM
- - edstrick   That's not what I recall.... but given "N...   Apr 15 2006, 08:25 AM
- - BruceMoomaw   There was a very detailed "Science News...   Apr 15 2006, 08:54 AM
- - edstrick   I have an original copy of that Icarus special iss...   Apr 15 2006, 10:10 AM
- - AlexBlackwell   Again, I apologize for reviving a dormant thread; ...   Jul 18 2006, 01:53 AM
|- - JRehling   QUOTE (AlexBlackwell @ Jul 17 2006, 06:53...   Jul 18 2006, 02:50 PM
||- - helvick   QUOTE (JRehling @ Jul 18 2006, 03:50 PM) ...   Jul 18 2006, 04:05 PM
|- - AlexBlackwell   QUOTE (AlexBlackwell @ Jul 17 2006, 03:53...   May 4 2007, 08:41 PM
|- - JRehling   QUOTE (AlexBlackwell @ May 4 2007, 01:41 ...   May 6 2007, 09:19 PM
|- - JRehling   QUOTE (JRehling @ May 6 2007, 02:19 PM) S...   May 10 2007, 08:31 PM
- - Mariner9   I had a chance to talk to one of the engineers on ...   Jul 18 2006, 06:39 PM
|- - AlexBlackwell   QUOTE (Mariner9 @ Jul 18 2006, 08:39 AM) ...   Jul 18 2006, 09:07 PM
||- - SFJCody   QUOTE (AlexBlackwell @ Jul 18 2006, 10:07...   Jul 18 2006, 10:07 PM
|||- - AlexBlackwell   QUOTE (SFJCody @ Jul 18 2006, 12:07 PM) I...   Jul 18 2006, 10:13 PM
||- - centsworth_II   QUOTE (AlexBlackwell @ Jul 18 2006, 05:07...   Jul 19 2006, 08:34 PM
||- - Richard Trigaux   QUOTE (centsworth_II @ Jul 19 2006, 08:34...   Jul 19 2006, 08:43 PM
||- - JRehling   QUOTE (Richard Trigaux @ Jul 19 2006, 01...   Jul 19 2006, 09:45 PM
|- - JRehling   QUOTE (Mariner9 @ Jul 18 2006, 11:39 AM) ...   Jul 19 2006, 06:12 PM
- - Richard Trigaux   Will the effect of these bulges be detectable by a...   Jul 20 2006, 06:02 AM
|- - JRehling   QUOTE (Richard Trigaux @ Jul 19 2006, 11...   Jul 20 2006, 02:27 PM
|- - Richard Trigaux   A doppler analysis of a permanent signal will give...   Jul 20 2006, 03:48 PM
|- - JRehling   QUOTE (Richard Trigaux @ Jul 20 2006, 08...   Jul 20 2006, 07:52 PM
- - mcaplinger   I think you guys are at least a few orders of magn...   Jul 20 2006, 08:26 PM
- - Richard Trigaux   JRehling, I think that sensing several bulges movi...   Jul 21 2006, 06:19 AM
|- - mcaplinger   QUOTE (Richard Trigaux @ Jul 20 2006, 11...   Jul 21 2006, 02:20 PM
- - Mariner9   http://www.aip.org/fyi/2006/093.html I just found...   Aug 1 2006, 07:06 PM
|- - Lorne Ipsum   QUOTE (Mariner9 @ Aug 1 2006, 01:06 PM) ....   Sep 17 2006, 09:03 PM
- - Roly   Any further news about JunoCam pictures of the sat...   Sep 18 2006, 02:42 AM
|- - mcaplinger   QUOTE (Roly @ Sep 17 2006, 07:42 PM) Any ...   Sep 18 2006, 02:50 PM
|- - JRehling   QUOTE (mcaplinger @ Sep 18 2006, 07:50 AM...   Sep 18 2006, 04:40 PM
- - gndonald   I find the current 'tussle' on the forum a...   Sep 19 2006, 04:07 PM
- - Analyst   QUOTE (gndonald @ Sep 19 2006, 04:07 PM) ...   Sep 19 2006, 06:15 PM
|- - tedstryk   I know the images are not a priority, but there ar...   Sep 19 2006, 08:14 PM
|- - gndonald   QUOTE (Analyst @ Sep 20 2006, 02:15 AM) V...   Sep 21 2006, 03:13 PM
- - Mariner9   I recall reading about that proposed orbiter. I v...   Sep 21 2006, 05:11 PM
- - Mariner9   I think I was a little vague about the main point ...   Sep 21 2006, 05:14 PM
- - Analyst   QUOTE (gndonald @ Sep 21 2006, 03:13 PM) ...   Sep 21 2006, 06:18 PM
|- - Roly   Given Junocam's heritage from MSL's MARDI,...   Sep 24 2006, 12:26 PM
- - vjkane2000   Juno's camera has been quoted on their website...   Nov 2 2006, 03:39 PM
|- - Lorne Ipsum   QUOTE (vjkane2000 @ Nov 2 2006, 09:39 AM)...   Nov 3 2006, 12:18 AM
|- - ugordan   If the perijove is well inside Io's orbit, doe...   Nov 3 2006, 08:33 AM
|- - vjkane2000   QUOTE (Lorne Ipsum @ Nov 2 2006, 04:18 PM...   Nov 3 2006, 03:50 PM
- - edstrick   The Voyagers got considerable amounts of sampled h...   Nov 4 2006, 11:33 AM
|- - vjkane2000   QUOTE (edstrick @ Nov 4 2006, 03:33 AM) T...   Nov 4 2006, 08:49 PM
- - NMRguy   As discussed above, imaging with JunoCam is a peri...   Nov 10 2006, 09:28 AM
|- - Bjorn Jonsson   An obvious problem is that Jupiter's poles nev...   Nov 10 2006, 03:26 PM
|- - Lorne Ipsum   QUOTE (NMRguy @ Nov 10 2006, 03:28 AM) Do...   Dec 26 2006, 10:06 PM
- - nprev   I would imagine that IR-band imaging would be an i...   Nov 10 2006, 04:04 PM
- - John Flushing   I dug out an article from June of 2005. New robot...   Jan 10 2007, 12:34 AM
- - Thu   A new article for Juno: Juno Gets A Little Bigger ...   Mar 12 2007, 11:05 AM
|- - Lorne Ipsum   QUOTE (Thu @ Mar 12 2007, 04:05 AM) I...   Mar 12 2007, 11:22 AM
|- - AndyG   QUOTE (Thu @ Mar 12 2007, 11:05 AM) - How...   Mar 12 2007, 11:31 AM
- - helvick   20% efficiency is conservative, the state of the a...   Mar 12 2007, 12:20 PM
|- - vjkane2000   QUOTE (helvick @ Mar 12 2007, 04:20 AM) ...   Mar 12 2007, 04:30 PM
- - Thu   Thanks Lorne Ipsum, that really helps   Mar 12 2007, 12:24 PM
- - djellison   There's also the issue of how much of that 3 x...   Mar 12 2007, 12:56 PM
|- - centsworth_II   QUOTE (djellison @ Mar 12 2007, 08:56 AM)...   Mar 12 2007, 04:26 PM
|- - Analyst   QUOTE (djellison @ Mar 12 2007, 01:56 PM)...   Mar 13 2007, 06:02 PM
- - Thu   Talking of solar power, I remembered that Deep Spa...   Mar 12 2007, 02:09 PM
- - edstrick   Bruce Moomaw has a couple articles worth checking ...   Mar 13 2007, 08:44 AM
- - helvick   This Boeing\Spectrolab marketing page indicat...   Mar 13 2007, 10:57 AM
- - NMRguy   As far as I can tell, the Juno team has always pla...   Mar 13 2007, 10:03 PM
- - edstrick   Early deep space missions (not including REALLY ea...   Mar 14 2007, 09:35 AM
- - Phil Stooke   Ed, the Mariner 5 dual-frequency occultation exper...   Mar 15 2007, 03:35 AM
- - edstrick   I'm an images type of guy, but with 20-20 hind...   Mar 15 2007, 08:31 AM
|- - tedstryk   I would add that until Venus was nearly frame fill...   Mar 15 2007, 01:48 PM
- - edstrick   "...Venus was nearly frame filling, it is que...   May 7 2007, 07:43 AM
|- - tedstryk   Based on what I have read, the Mariner-R (the desi...   May 8 2007, 01:45 PM
|- - Paolo   QUOTE (tedstryk @ May 8 2007, 03:45 PM) B...   May 8 2007, 06:33 PM
|- - tedstryk   QUOTE (Paolo @ May 8 2007, 06:33 PM) As f...   May 8 2007, 08:27 PM
- - edstrick   I have a xerox of an article from some journal lik...   May 9 2007, 08:12 AM
- - volcanopele   What's the field of view of JunoCam and what i...   May 10 2007, 08:43 PM
|- - AlexBlackwell   QUOTE (volcanopele @ May 10 2007, 10:43 A...   May 10 2007, 08:51 PM
|- - AlexBlackwell   QUOTE (AlexBlackwell @ May 10 2007, 10:51...   May 10 2007, 09:50 PM
- - volcanopele   hmm, a push-broom detector? Assuming each image i...   May 10 2007, 09:09 PM
- - djellison   JunoCam is a MARDI rip off isn't it? 1600 x 12...   May 10 2007, 09:15 PM
- - vjkane   What would be the resolution of JunoCAM at closest...   May 11 2007, 01:49 AM
- - AlexBlackwell   Note that the Juno website was recently updated.   Sep 13 2007, 06:46 PM
- - nprev   Little bit bummed that there isn't a radio DF ...   Sep 14 2007, 12:03 AM
- - Del Palmer   NASA awards Atlas V contract for Juno: http://www...   Oct 3 2007, 09:51 PM
- - NMRguy   QUOTE (Del Palmer @ Oct 3 2007, 11:51 PM)...   Oct 4 2007, 10:38 PM
- - mchan   QUOTE (NMRguy @ Oct 4 2007, 03:38 PM) Non...   Oct 5 2007, 10:39 AM
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