Juno development, launch, and cruise, Including Earth flyby imaging Oct 9 2013 |
Juno development, launch, and cruise, Including Earth flyby imaging Oct 9 2013 |
Apr 3 2006, 09:57 PM
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Member Group: Members Posts: 172 Joined: 17-March 06 Member No.: 709 |
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_Richard Trigaux_* |
Jul 21 2006, 06:19 AM
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Guests |
JRehling, I think that sensing several bulges moving around Jupiter is actually a three dimentional problem (or at least two, if we assume a symmetry regarding the equatorial plane).
mcaplinger, in fact you reply my previous question: "is Juno position measurement accurate enough to sense high ranking harmonics and detect tidal effects?". After your reply, it is not, and by several order of magnitude. detecting only the first three harmonics will only allow to sense the inner spherical layer structure, and even not very accurately. No hope to detect vortexes or other exotic things. To achieve a better accuracy would require that Juno sense three pulsars with a high accuracy, or three natural masers. But I am afraid that this would involve very large antennas, much too large for a ship like Juno. The only practical solution would be to have a kind of GPS positioning around Jupiter. I already said several times in this forum that a GPS positioning and radio relay (with large data storage) would be one of the first things to do for seriously exploring any planet. Such small satellites would be designed to last for tens of years, for further missions. On Jupiter, this is especially difficult, with the radiation belts. But could be a ship like Juno be left in orbit, once it exhausted its fuel, and be used as such a relay? This would just require some tens of kilos of additional mass, and be very useful for further missions. |
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Jul 21 2006, 02:20 PM
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Senior Member Group: Members Posts: 2542 Joined: 13-September 05 Member No.: 497 |
To achieve a better accuracy would require that Juno sense three pulsars with a high accuracy, or three natural masers... The only practical solution would be to have a kind of GPS positioning around Jupiter. I don't think either of these solutions would work to solve the problem you're describing. You can't determine your location by observing pulsars from a single point with any kind of accuracy. You may be thinking of VLBI, which is used for geodesy on the Earth, but this requires simultaneuous observations from several locations and high bandwidth communications between them. As to GPS, one of the components of such a system is knowledge of the transmitting satellites' positions. So without a fixed location from which to track them, I think there may be a chicken-and-egg problem if you are trying to get very high positional precision (even on Earth, GPS can't do better than a half meter or so even using DGPS.) There may be some sort of multiple-satellite, multiple-transmitter solution to this problem, but that would require a very large investment to build. The bottom line is that I just don't think it's practical to study this problem using gravity sensing with our current level of technology. Fortunately there are other ways; see the Juno reference I mentioned earlier. -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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