Nasa Picks "juno" As Next New Frontiers Mission |
Nasa Picks "juno" As Next New Frontiers Mission |
Guest_BruceMoomaw_* |
Jun 1 2005, 10:10 PM
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Guests |
http://www.nasa.gov/home/hqnews/2005/jun/H...rontiers_2.html
Yeah, I know it ain't Saturn, but we don't seem to have any proper slot for Jovian news -- including yesterday's totally unexpected announcement that Amalthea's density is so low as to suggest that it's a highly porous ice object; maybe a captured Kuiper Belt Object reduced to rubble by infalling meteoroids. As Jason Perry says, this might explain those previously mysterious light-colored patches on Amalthea -- they may be its underlying ice, exposed by impacts that punched through the layer of sulfur spray-painted onto it by Io. Scott Bolton has been pretty talkative to me already about the design of Juno. It certainly won't be as good in the PR department as Galileo or Cassini, but it DOES carry a camera -- as much for PR as for Jovian cloud science, according to Bolton. And since the latitude of periapsis of its highly elliptical orbit will change radically during the primary mission, I wonder if they might be able to set up at least one close photographic flyby of Io and/or Amalthea? (I believe, by the way, that this selection is a bit ahead of schedule -- and it certainly indicates that NASA's science program under Griffin won't be a complete slave to Bush's Moon-Mars initiative.) |
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Guest_BruceMoomaw_* |
Jun 11 2005, 09:04 PM
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#2
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Guests |
Juno's orbit will go from only 4500 km above Jupiter's 1-bar air pressure level (it will be even closer to the tops of the ammonia clouds) all the way out to 30 Jupiter radii from the planet. (They need to get that close to ensure really high-resolution gravity and magnetic maps of Jupiter -- it's the same orbit planned for the "INSIDE Jupiter" mission that was a Discovery finalist twice and has now been combined with two other Jovian Discovery proposals to create Juno.)
That periapsis will wander somewhat in latitude, although I haven't got specific figures yet -- but I believe it's enough to theoretically allow flybys of any mooon out to Callisto. PI Scott Bolton tells me that there are currently no plans for flybys of any of the moons (although, during our previous conversations, he had expressed some interest in the idea during the extended mission); but the description in Space.com says that Juno's camera may be used for longer-distance photos of Io and Amalthea. It's important to remember that this mission has radically different goals from any mission to study Europa or the other moons -- its purpose is to study JUPITER, by God, and specifically its composition and the size of its rock/ice core, which are extremely important in answering questions about how the giant planets actually formed. (This is one of the most important questions for planetary scientists right now, and there are two radically different theories.) Also Jupiter's polar magnetosphere, which the NASA's Sun-Solar Systems Directorate -- separately from its Solar System Directorate -- has also declared to be an extremely important short-term goal for its own researches and worthy of a mission. To achieve all this, it needs an orbit completely different from those that would be used by a moon-studying orbiter -- and since such a mission is also simpler and cheaper, they decided, entirely logically, to fly it first. As for the Europa mixup, John Rehling doesn't mention the biggest villain of all: Dan Goldin, aka "Captain Crazy". NASA's science advisory board recommended officially -- and entirely sensibly -- that a Pluto mission, which required no new technology at all, should be flown BEFORE the Europa Orbiter, and specifically in 2003. Dan Goldin, however, was determined to reverse their order because of his personal obsession with astrobiology at all costs -- "Nobody gives a damn about Pluto", he told his staffers. (His repeated urgings that NASA should use radically new technologies, entirely unnecessarily, to build a teeny-weeny Pluto probe --"the size of my fist", to quote one disgruntled researcher -- were, as he privately told his staffers, just a cover for the fact that he intended to kill the Pluto mission completely.) The result, given the very real and major new technological difficulties in flying a Europa Orbiter, were that we didn't get either mission -- or rather that the Pluto mission was delayed until 2006 and finally rammed through by Congress over the dead bodies of Goldin, Sean O'Keefe and President Bush, which means both a more expensive Pluto mission and a distinctly scientifically inferior one to what we would have had had it been launched in 2003 or 2004. The case for such a mission, both scientifically and fiscally, was so strong that even the GOP Congress was finally firmly convinced of the idiocy of not flying it. (To my continuing amazement, I myself ended up playing a significant role in getting that decision made -- largely due to a SpaceDaily article I published in 2000 pointing out that either the Stardust or CONTOUR comet probe could be easily redesigned to fly a Pluto mission cheaply -- which is why I have a free ticket to its launch next January. No doubt other people had come up with the same idea; but Goldin, it later turned out, had been threatening to cut off their grants if they didn't keep their mouths shut. They had no such leverage over me, and so I ended up -- entirely accidentally -- belling the cat. But I digress.) Anyway, as a result of Goldin's monomania, we ended up getting both a Pluto mission later and worse and more expensive than we could have had it, but also probably some unnecesary delays to Europa Orbiter -- which were then made worse by the fact that O'Keefe, due to his total lack of engineering training, fell for the cretinous JIMO scheme to fly a nuclear-powered battleship to Jupiter, even though the science community had officially stated that it didn't want it. (In this respect, as in many others, he got rolled by his unscrupulous NASA underlings; but one scientist has told me that O'Keefe's nuclear-enthusiast brother also helped talk him into it.) Now -- years later than we could have been -- we're back to Square One where Europa Orbiter is concerned. What Ed Strick says is also true: the first version of Europa Orbiter was cancelled becuase it had a $1 billion cost cap, which simply could not be met. Now NASA's new Solar System Roadmap calls for it to be the first of the new class of "Small Flagship" Solar System mission -- costing between $700 million and $ 1.5 billion -- to be launched at 5-year intervals. Europa Orbiter is recommended for launch in 2014 (and it looks more and more as though the ESA will collaborate with us on it). The second Small Flagship is likely to be to Titan in 2019, and the third to Venus in 2024. |
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Jun 15 2005, 02:51 PM
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#3
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Junior Member Group: Members Posts: 81 Joined: 25-February 05 From: New Jersey Member No.: 177 |
QUOTE (BruceMoomaw @ Jun 11 2005, 09:04 PM) Juno's orbit will go from only 4500 km above Jupiter's 1-bar air pressure level (it will be even closer to the tops of the ammonia clouds) all the way out to 30 Jupiter radii from the planet. (They need to get that close to ensure really high-resolution gravity and magnetic maps of Jupiter -- it's the same orbit planned for the "INSIDE Jupiter" mission that was a Discovery finalist twice and has now been combined with two other Jovian Discovery proposals to create Juno.) That periapsis will wander somewhat in latitude, although I haven't got specific figures yet -- but I believe it's enough to theoretically allow flybys of any mooon out to Callisto. PI Scott Bolton tells me that there are currently no plans for flybys of any of the moons (although, during our previous conversations, he had expressed some interest in the idea during the extended mission); but the description in Space.com says that Juno's camera may be used for longer-distance photos of Io and Amalthea. It's important to remember that this mission has radically different goals from any mission to study Europa or the other moons -- its purpose is to study JUPITER, by God, and specifically its composition and the size of its rock/ice core, which are extremely important in answering questions about how the giant planets actually formed. (This is one of the most important questions for planetary scientists right now, and there are two radically different theories.) Also Jupiter's polar magnetosphere, which the NASA's Sun-Solar Systems Directorate -- separately from its Solar System Directorate -- has also declared to be an extremely important short-term goal for its own researches and worthy of a mission. To achieve all this, it needs an orbit completely different from those that would be used by a moon-studying orbiter -- and since such a mission is also simpler and cheaper, they decided, entirely logically, to fly it first. As for the Europa mixup, John Rehling doesn't mention the biggest villain of all: Dan Goldin, aka "Captain Crazy". NASA's science advisory board recommended officially -- and entirely sensibly -- that a Pluto mission, which required no new technology at all, should be flown BEFORE the Europa Orbiter, and specifically in 2003. Dan Goldin, however, was determined to reverse their order because of his personal obsession with astrobiology at all costs -- "Nobody gives a damn about Pluto", he told his staffers. (His repeated urgings that NASA should use radically new technologies, entirely unnecessarily, to build a teeny-weeny Pluto probe --"the size of my fist", to quote one disgruntled researcher -- were, as he privately told his staffers, just a cover for the fact that he intended to kill the Pluto mission completely.) The result, given the very real and major new technological difficulties in flying a Europa Orbiter, were that we didn't get either mission -- or rather that the Pluto mission was delayed until 2006 and finally rammed through by Congress over the dead bodies of Goldin, Sean O'Keefe and President Bush, which means both a more expensive Pluto mission and a distinctly scientifically inferior one to what we would have had had it been launched in 2003 or 2004. The case for such a mission, both scientifically and fiscally, was so strong that even the GOP Congress was finally firmly convinced of the idiocy of not flying it. (To my continuing amazement, I myself ended up playing a significant role in getting that decision made -- largely due to a SpaceDaily article I published in 2000 pointing out that either the Stardust or CONTOUR comet probe could be easily redesigned to fly a Pluto mission cheaply -- which is why I have a free ticket to its launch next January. No doubt other people had come up with the same idea; but Goldin, it later turned out, had been threatening to cut off their grants if they didn't keep their mouths shut. They had no such leverage over me, and so I ended up -- entirely accidentally -- belling the cat. But I digress.) Anyway, as a result of Goldin's monomania, we ended up getting both a Pluto mission later and worse and more expensive than we could have had it, but also probably some unnecesary delays to Europa Orbiter -- which were then made worse by the fact that O'Keefe, due to his total lack of engineering training, fell for the cretinous JIMO scheme to fly a nuclear-powered battleship to Jupiter, even though the science community had officially stated that it didn't want it. (In this respect, as in many others, he got rolled by his unscrupulous NASA underlings; but one scientist has told me that O'Keefe's nuclear-enthusiast brother also helped talk him into it.) Now -- years later than we could have been -- we're back to Square One where Europa Orbiter is concerned. What Ed Strick says is also true: the first version of Europa Orbiter was cancelled becuase it had a $1 billion cost cap, which simply could not be met. Now NASA's new Solar System Roadmap calls for it to be the first of the new class of "Small Flagship" Solar System mission -- costing between $700 million and $ 1.5 billion -- to be launched at 5-year intervals. Europa Orbiter is recommended for launch in 2014 (and it looks more and more as though the ESA will collaborate with us on it). The second Small Flagship is likely to be to Titan in 2019, and the third to Venus in 2024. Why is it spinning? Granted, the science to be done doesn't require imaging, but you CAN do some really good science with cameras. Recall the differences in what we learned between Pioneer and Voyager, much of which was due to the fact that Voyager had a camera. How much more would it cost to build a three-axis stabilized craft? If it is spinning, are our computer processing techniques good enough to reconstruct images better than we could with Pioneer. Or can I say the magic words "scan platform".... Who will be in charge of building the small flagships? Are these going to be MRO-class missions, or more like Discovery missions to the outer planets? I'm assuming Juno will have some RTGs to play with? What does the instrumentation look like on the possible Europa orbiter? It needs a radar, and of course a camera. -------------------- ----------------------------------------------
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