Cassini's Extended-Extended Mission, July 2010-June 2017 |
Cassini's Extended-Extended Mission, July 2010-June 2017 |
Feb 5 2010, 07:28 PM
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#106
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Solar System Cartographer Group: Members Posts: 10151 Joined: 5-April 05 From: Canada Member No.: 227 |
"one of the driving considerations behind the end-of-mission scenarios is to avoid even the small
probability of hitting Europa " That would need one heck of a gravity assist to hit Europa! Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PD: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Feb 5 2010, 10:51 PM
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#107
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Senior Member Group: Members Posts: 1419 Joined: 26-July 08 Member No.: 4270 |
QUOTE Dumping your RTG-powered spacecraft in a giant planet avoids lawsuits, terrorist threats, and planetary protection issues. I recall accusations that the devious, dastardly NASA was trying to "destroy Jupiter" or turn it into a sun by dropping a "nuke" into it with the Galileo plunge. -------------------- -- Hungry4info (Sirius_Alpha)
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Feb 5 2010, 11:04 PM
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#108
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Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
One thing to keep foremost in mind is that the PPPs & similar protocols are designed with full knowledge of the abundance of ignorance that we currently possess with regard to the tolerances/constraints required to not irrevocably screw up pristine extraterrestrial environments.
In that sense, they represent considerable foresight & forebearance. Minimizing changes to systems with complex (and not even close to being fully understood) interdependent attributes seems exceptionally wise. -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Feb 5 2010, 11:13 PM
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#109
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Member Group: Members Posts: 813 Joined: 29-December 05 From: NE Oh, USA Member No.: 627 |
I think the science we will get during the close Saturn passes will be magnificent. And those close passes I assume are risky. Not sure if CASSINI could be pulled out of that orbital configuration once she takes those dives.
Nothing lasts forever. I would rather a last grand dive into Saturn than a lonely and useless orbit of the Sun. Even if that were possible in the end. Craig |
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Feb 5 2010, 11:17 PM
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#110
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Member Group: Members Posts: 444 Joined: 1-July 05 From: New York City Member No.: 424 |
I recall accusations that the devious, dastardly NASA was trying to "destroy Jupiter" or turn it into a sun by dropping a "nuke" into it with the Galileo plunge. Similar comments about the Cassini plunge are easy to find. I'll post no links, because I assume the subject is out of bounds for umsf.com. TTT |
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Feb 5 2010, 11:20 PM
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#111
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Member Group: Members Posts: 813 Joined: 29-December 05 From: NE Oh, USA Member No.: 627 |
I recall accusations that the devious, dastardly NASA was trying to "destroy Jupiter" or turn it into a sun by dropping a "nuke" into it with the Galileo plunge. There were indeed. Even suggestions that the rtg's caused a nuclear explosion inside Jupiter's atmosphere. Curious whether the same claims will be repeated in 2017. Craig |
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Feb 5 2010, 11:35 PM
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#112
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Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Well...let's just say that it's a statistical certainty that incredulous claims will be made by those who lack credibility, and eagerly accepted by those who lack critical thinking skills.
(That reminds me: Time for my annual re-reading of Sagan's The Demon-Haunted World: Science As A Candle In The Dark. It's the only book I ever bought for each of my children.) Onward, anyhow. The XXM promises to provide something hitherto unprecedented for the outer planets: long-term observation of seasonal effects on not just one but at least three active worlds! That is what they call bang for the buck. -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Feb 6 2010, 12:40 AM
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#113
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Member Group: Members Posts: 593 Joined: 20-April 05 Member No.: 279 |
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Feb 12 2010, 06:19 PM
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#114
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Junior Member Group: Members Posts: 59 Joined: 12-November 09 Member No.: 5039 |
I recall accusations that the devious, dastardly NASA was trying to "destroy Jupiter" or turn it into a sun by dropping a "nuke" into it with the Galileo plunge. Yeah, our friend Hoaxland at his best Of course the fact that Pu-238 is not even a fissile isotope didn't stop his hyperactive imagination... |
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Feb 13 2010, 04:38 AM
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#115
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
Just noticed it's gonna be a "crashy" 2017 ... one month after Cassini enters Saturn's atmosphere (15 Sep 2017), it is Juno's time to disintegrate in Jupiter's atmosphere (16 Oct 2017)
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Feb 13 2010, 05:30 AM
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#116
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
Yeah, it's pretty awesome that Cassini will be in a Juno-like orbit at the same time Juno is in a Juno-like orbit; it will be fascinating to compare the behavior of the two giant planets' magnetic fields and plasma environments under identical solar conditions. Fascinating, that is, if you're a plasma physicist. Not my cup of tea. But I'm excited on their behalf
-------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Feb 13 2010, 05:42 AM
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#117
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Senior Member Group: Moderator Posts: 2785 Joined: 10-November 06 From: Pasadena, CA Member No.: 1345 |
So assuming all the orbiting missions get extended, by then we could have 6 planetary bodies being orbited by spacecraft. Awesome!
-------------------- Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
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Nov 4 2010, 11:12 PM
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#118
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Senior Member Group: Members Posts: 1582 Joined: 14-October 05 From: Vermont Member No.: 530 |
That's a purely gravitational nudge from Titan- no propellant required. That final "close" approach to Titan will be at a range of 86,000 km. However, it looks like they're perhaps going to try and measure exactly what their margin was! QUOTE Tuesday, Nov. 2 (DOY 306)
The results of a study of maneuvers near end of mission were presented at the Mission Planning Forum this week. The topics were the delta-v impact of accidental burn-to-depletions and a possible planned burn-to-depletion near the end of mission. An accidental burn-to-depletion occurs when either insufficient fuel or oxidizer remains to produce the thrust level required during a main engine maneuver. The study looked at the delta-v impact of completing the interrupted maneuver at a later time using hydrazine and the RCS thrusters. A planned burn-to-depletion concept was also discussed in the event that bipropellant remains at the very end of the mission. This burn, if performed, would be done during the last proximal orbit to determine how much usable propellant remained in the tank. The study identified times during the last orbit where the burn could be performed and impact into Saturn's atmosphere would still be assured. There are many issues to consider for both of these concepts and the topic will be studied in more detail when the project looks to plan the later segments of the mission. |
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Sep 24 2016, 07:20 PM
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#119
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Junior Member Group: Members Posts: 66 Joined: 3-August 12 Member No.: 6454 |
The recent NASA-JPL webcast presentation about the Cassini mission's "Grand Finale" featured, among many other interesting things, a slide with a diagram of the 2017 "proximal orbits".
I thought that diagram was really interesting, so I saved a couple of screen grabs. Does anyone here know if the diagram is available in hi-rez form somewhere? Also, does the size of the blue dots represent navigation error probable size? Thanks very much. |
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Oct 21 2016, 09:10 PM
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#120
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Senior Member Group: Members Posts: 1887 Joined: 20-November 04 From: Iowa Member No.: 110 |
From the DPSEPSC conference;
QUOTE Spilker: Last Cassini images on plunge will be ~10hrs before, followed by downlink, then desperate in situ samples before *the end* https://twitter.com/LeighFletcher/status/789569457425227776 |
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