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NASA Dawn Asteroid Mission Told to "Stand Back Up", Reinstated!
dvandorn
post Mar 28 2006, 07:58 AM
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Just 'cause I said I would... biggrin.gif biggrin.gif biggrin.gif biggrin.gif biggrin.gif biggrin.gif

Hopefully, though, this whole episode has made its point -- NASA isn't afraid to tell overbudget missions to stand down.

I just *really* wish we could get the magnetometer back on the beastie, though...

-the other Doug


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“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Mariner9
post Mar 31 2006, 03:47 PM
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I remember in one of the earlier Discovery mission proposals I read about a mission similar to CONTOUR which would flyby multiple asteroids. It wouldn't seem all that cost effective to only fly by 2-3 asteroids, but I know that in the early days of DAWN they were suggesting that they could fly past as many as 10-12 targets on the way there. I always found that number as overly optimistic, Dawn will have enough on it's plate just getting there, so if they manage 1-2 extra flybys it would be impressive enough. Something I read recently suggested they were now using lower numbers whenever the topic came up.

But has anyone given any serious consideration to taking a Dawn type ion propelled spacecraft and using all of the delta-vee specifically for as many fly-bys as possible? I would think with a couple Earth, Venus, or Mars flybys thrown in to make the orbit more elipitcal, they could potentially survey a very large number of targets.

It occurs to me that the instrumentation on DAWN might not be the best for fast flybys, but with the right package this might yield a lot more targets and results than a simple ballistic probe like CONTOUR. And that might make it worth it.

All of this is assuming that the Discovery office at NASA isn't really gun shy about ion drive missions right now.
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JRehling
post Mar 31 2006, 05:47 PM
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QUOTE (Mariner9 @ Mar 31 2006, 07:47 AM) *
But has anyone given any serious consideration to taking a Dawn type ion propelled spacecraft and using all of the delta-vee specifically for as many fly-bys as possible? I would think with a couple Earth, Venus, or Mars flybys thrown in to make the orbit more elipitcal, they could potentially survey a very large number of targets.


Yeah, if you pick targets according to trajectories that net the highest sheer number, without any particular targets offering constraints, I would expect some fantastic possibilities.

Thinking outside the box, I wonder about using a Jupiter gravity assist to create a retrograde orbit that could be later circularized or near-circularized with propulsion and/or Earth gravity assists. It seems to me that flying backwards through the asteroid belt would very much increase the number of flyby possibilities, the same way that you would pass close to a LOT more cars on the highway driving 70 mph against traffic than you would driving 90 mph with traffic. In fact, this would mean no propellant would be needed to catch up to asteroids, or to lag behind them, and all of the propellant (once you achieve that orbit) could be used in "lateral" motion to create flybys. With 10,000 targets, and a full lap relative to the field taking place in about 2.5 years, the craft in retrograde orbit would fly by the radial vector of another asteroid every 2.5 hours! Assuming the asteroid belt is 1 AU wide, totally planar and with uniform distribution of the asteroids within it, the craft would fly within 0.001 AU (149,000 km) of an asteroid about three times a year even if you did nothing to aim for any targets! I would think that a campaign of lateral manuevers aiming for targets well in advance could lead to a mission ultimately achieving hundreds of flybys in a main mission of ten years.

Feasible?
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Bob Shaw
post Mar 31 2006, 10:57 PM
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QUOTE (JRehling @ Mar 31 2006, 06:47 PM) *
Thinking outside the box, I wonder about using a Jupiter gravity assist to create a retrograde orbit that could be later circularized or near-circularized with propulsion and/or Earth gravity assists.

Feasible?


Now *that* is a really clever idea!

Simple, cheap, and (almost) free.

Any serious orbital dynamics guys out there? Or girls, I care not which!

Bob Shaw


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David
post Apr 1 2006, 12:06 AM
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Not me, but one thing occurs to me: aren't these byflights going to be awfully fast?
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Posts in this topic
- dvandorn   NASA Dawn Asteroid Mission Told to "Stand Back Up"   Mar 28 2006, 07:58 AM
- - Holder of the Two Leashes   Does anyone know how much it would cost to reinsta...   Mar 28 2006, 03:32 PM
|- - Marz   yee haw!! Has the mission timeline be...   Mar 28 2006, 04:15 PM
- - J.J.   ^ The launch has been pushed back to July 2007. T...   Mar 28 2006, 04:27 PM
|- - Marz   QUOTE (J.J. @ Mar 28 2006, 10:27 AM) ^ Th...   Mar 28 2006, 10:01 PM
|- - mchan   QUOTE (Marz @ Mar 28 2006, 02:01 PM) 3. a...   Mar 28 2006, 10:39 PM
|- - AlexBlackwell   QUOTE (Marz @ Mar 28 2006, 10:01 PM) 3. a...   Mar 28 2006, 10:55 PM
|- - The Messenger   QUOTE (Marz @ Mar 28 2006, 03:01 PM) Oh, ...   Mar 29 2006, 04:08 PM
|- - AlexBlackwell   QUOTE (The Messenger @ Mar 29 2006, 04:08...   Mar 29 2006, 07:04 PM
||- - SFJCody   Magnetometer or not, 2015 will put a significant c...   Mar 29 2006, 08:01 PM
||- - The Messenger   QUOTE (AlexBlackwell @ Mar 29 2006, 12:04...   Mar 29 2006, 08:05 PM
||- - AlexBlackwell   QUOTE (The Messenger @ Mar 29 2006, 08:05...   Mar 29 2006, 08:08 PM
||- - SFJCody   QUOTE (The Messenger @ Mar 29 2006, 09:05...   Mar 29 2006, 08:10 PM
|- - BruceMoomaw   QUOTE (The Messenger @ Mar 29 2006, 04:08...   Apr 1 2006, 12:48 AM
|- - AlexBlackwell   QUOTE (BruceMoomaw @ Apr 1 2006, 12:48 AM...   Apr 1 2006, 01:36 AM
|- - tedstryk   QUOTE (BruceMoomaw @ Apr 1 2006, 12:48 AM...   Apr 2 2006, 04:53 PM
- - AlexBlackwell   QUOTE (dvandorn @ Mar 28 2006, 07:58 AM) ...   Mar 28 2006, 04:49 PM
|- - SFJCody   QUOTE (AlexBlackwell @ Mar 28 2006, 05:49...   Mar 28 2006, 04:58 PM
||- - JRehling   QUOTE (SFJCody @ Mar 28 2006, 08:58 AM) I...   Mar 28 2006, 05:58 PM
|- - elakdawalla   QUOTE (AlexBlackwell @ Mar 28 2006, 08:49...   Mar 28 2006, 05:45 PM
|- - AlexBlackwell   QUOTE (elakdawalla @ Mar 28 2006, 05:45 P...   Mar 28 2006, 06:02 PM
- - gpurcell   http://dawn.jpl.nasa.gov/science/technology.asp S...   Mar 28 2006, 05:40 PM
- - peter59   I checked my calendar but it is not April Fool...   Mar 28 2006, 05:46 PM
- - BruceMoomaw   It is, I imagine, well too late to reinstall eithe...   Mar 28 2006, 08:11 PM
|- - AlexBlackwell   QUOTE (BruceMoomaw @ Mar 28 2006, 08:11 P...   Mar 28 2006, 09:30 PM
- - elakdawalla   Colleen Hartman said yesterday that the arrival da...   Mar 28 2006, 10:08 PM
|- - JRehling   QUOTE (elakdawalla @ Mar 28 2006, 02:08 P...   Mar 28 2006, 11:24 PM
|- - ElkGroveDan   QUOTE (JRehling @ Mar 28 2006, 11:24 PM) ...   Mar 28 2006, 11:39 PM
|- - dvandorn   QUOTE (JRehling @ Mar 28 2006, 05:24 PM) ...   Mar 29 2006, 02:26 AM
|- - antoniseb   QUOTE (dvandorn @ Mar 28 2006, 09:26 PM) ...   Mar 29 2006, 01:45 PM
|- - Bob Shaw   QUOTE (antoniseb @ Mar 29 2006, 02:45 PM)...   Mar 29 2006, 02:21 PM
- - mars loon   QUOTE (dvandorn @ Mar 28 2006, 07:58 AM) ...   Mar 29 2006, 12:47 AM
|- - Bjorn Jonsson   QUOTE (mars loon @ Mar 29 2006, 12:47 AM)...   Mar 29 2006, 12:48 PM
- - punkboi   All that matters is... The 'Send your name to ...   Mar 29 2006, 04:24 AM
- - nprev   You know, all these "Dawn ocean" jokes a...   Mar 29 2006, 06:40 AM
- - Myran   Ok great its back on track. And no more ocean joke...   Mar 29 2006, 11:34 AM
|- - dvandorn   QUOTE (Myran @ Mar 29 2006, 05:34 AM) ......   Mar 29 2006, 11:01 PM
- - BruceMoomaw   There's a great deal on this subject scattered...   Mar 29 2006, 06:52 PM
- - Mariner9   I second SFJCody's comment about a capstone ev...   Mar 29 2006, 08:45 PM
|- - SFJCody   QUOTE (Mariner9 @ Mar 29 2006, 09:45 PM) ...   Mar 29 2006, 09:51 PM
|- - JRehling   QUOTE (Mariner9 @ Mar 29 2006, 09:45 PM)W...   Mar 29 2006, 10:19 PM
- - BruceMoomaw   Actually, we still won't have done that. We h...   Mar 29 2006, 09:51 PM
- - Mariner9   Sigh. I considered putting in a caveate about th...   Mar 29 2006, 11:00 PM
- - BruceMoomaw   Actually, the Moomaw was just trying to point out ...   Mar 30 2006, 02:52 AM
|- - JRehling   I have a long-standing belief that I haven't h...   Mar 30 2006, 03:47 PM
- - Myran   QUOTE dvandorn said: in space, no one can hear you...   Mar 30 2006, 05:06 PM
|- - JRehling   QUOTE (Myran @ Mar 30 2006, 09:06 AM) Are...   Mar 30 2006, 05:12 PM
- - BruceMoomaw   One of the major mysteries of the belt is how Vest...   Mar 30 2006, 06:31 PM
- - Myran   QUOTE JRehling wrote: The total mass of the main b...   Mar 30 2006, 06:36 PM
|- - tedstryk   I think that it depends on how one defines samples...   Mar 30 2006, 08:39 PM
|- - JRehling   QUOTE (Myran @ Mar 30 2006, 10:36 AM) But...   Mar 30 2006, 11:39 PM
- - Mariner9   I remember in one of the earlier Discovery mission...   Mar 31 2006, 03:47 PM
|- - JRehling   QUOTE (Mariner9 @ Mar 31 2006, 07:47 AM) ...   Mar 31 2006, 05:47 PM
|- - Bob Shaw   QUOTE (JRehling @ Mar 31 2006, 06:47 PM) ...   Mar 31 2006, 10:57 PM
|- - David   Not me, but one thing occurs to me: aren't the...   Apr 1 2006, 12:06 AM
|- - JRehling   QUOTE (David @ Mar 31 2006, 04:06 PM) Not...   Apr 1 2006, 12:32 AM
- - BruceMoomaw   It's certainly an idea. One might even combin...   Mar 31 2006, 08:12 PM
- - BruceMoomaw   Oh, yes. Might be worth doing anyway, though, if ...   Apr 1 2006, 12:16 AM
- - BruceMoomaw   I've considered trying to look into the questi...   Apr 1 2006, 02:22 AM
- - BruceMoomaw   That, in turn returns us to the question I mention...   Apr 2 2006, 08:13 PM
|- - Bob Shaw   Bruce: 'Harder metal cores?' That's a...   Apr 2 2006, 08:57 PM
- - BruceMoomaw   As a matter of fact, the fact that a lot of the as...   Apr 2 2006, 11:34 PM
- - Bart   A new edition of the Dawn's Early Light newsle...   Apr 6 2006, 10:23 PM
|- - mchan   The newsletter notes what was posted earlier in th...   Apr 8 2006, 02:16 AM
- - gpurcell   Looks like they whacked the program managers from ...   Apr 7 2006, 04:23 PM
- - Marz   So Oct 31, 2007 is a scary date indeed! I...   Apr 9 2006, 02:58 PM
- - BruceMoomaw   Andy Dantzler just provided an "explanation...   Apr 11 2006, 08:37 PM
- - gpurcell   QUOTE The other thing is when you do overrun - if ...   Apr 11 2006, 10:38 PM
|- - BruceMoomaw   [quote name= quote in reply - removed [/quote] No...   Apr 12 2006, 12:05 AM
- - gpurcell   Well, if he can still get two new vehicles out of ...   Apr 12 2006, 03:07 PM
- - Analyst   What has been the problem with the Discovery 11 AO...   Apr 18 2006, 10:59 AM
|- - BruceMoomaw   QUOTE (Analyst @ Apr 18 2006, 10:59 AM) W...   Apr 18 2006, 09:48 PM
|- - ugordan   QUOTE (BruceMoomaw @ Apr 18 2006, 10:48 P...   Apr 20 2006, 09:31 AM
- - monitorlizard   Without trying to provoke anger, I think Dawn was ...   Apr 18 2006, 12:38 PM
|- - Bob Shaw   QUOTE (monitorlizard @ Apr 18 2006, 01:38...   Apr 18 2006, 01:12 PM
|- - tedstryk   QUOTE (monitorlizard @ Apr 18 2006, 12:38...   Apr 18 2006, 02:48 PM
- - Analyst   Thank you, Bruce.   Apr 20 2006, 08:00 AM
- - Analyst   I guess it's not rising but falling demand. A ...   Apr 20 2006, 03:17 PM
- - BruceMoomaw   "Analyst" is correct -- as the demand fo...   Apr 20 2006, 08:31 PM
|- - Bob Shaw   Bruce: SeaLaunch on Zenit-2. Bob Shaw   Apr 20 2006, 08:40 PM
|- - RNeuhaus   QUOTE (Bob Shaw @ Apr 20 2006, 03:40 PM) ...   Apr 22 2006, 02:19 AM
|- - tedstryk   [quote name='RNeuhaus' _quote in reply -re...   Apr 22 2006, 02:21 AM
- - djellison   Sea Launch is 5200kg to GTO Delta II Heavy - 2064 ...   Apr 20 2006, 10:36 PM
|- - Bob Shaw   QUOTE (djellison @ Apr 20 2006, 11:36 PM)...   Apr 21 2006, 07:43 PM
|- - Jim from NSF.com   QUOTE (Bob Shaw @ Apr 21 2006, 03:43 PM) ...   Apr 22 2006, 07:57 PM
- - edstrick   The europeans ran into the same "oops.... how...   Apr 21 2006, 10:40 AM
- - BruceMoomaw   Yeah, but most Solar System launches have limited ...   Apr 22 2006, 02:06 AM
- - remcook   zenit is the rocket model   Apr 22 2006, 03:46 PM
- - tty   How about Long March 2 - 3370 kg to GTO tty   Apr 22 2006, 05:13 PM
- - ljk4-1   Mark Rayman has created his first log of the renew...   Apr 27 2006, 01:54 PM
- - Rakhir   Dawn Team Looking Good For Launch Next Year http:...   Jun 1 2006, 08:38 AM
|- - Marz   QUOTE (Rakhir @ Jun 1 2006, 03:38 AM) Daw...   Jun 1 2006, 03:50 PM
- - PhilHorzempa   Some recently posted images on DAWN website showin...   Jun 29 2006, 03:43 AM
|- - punkboi   QUOTE (PhilHorzempa @ Jun 28 2006, 08:43 ...   Jun 29 2006, 05:42 PM
- - PhilHorzempa   There have been several very good photos of DAWN r...   Aug 1 2006, 03:38 AM
- - djellison   Is it really necessary to attach these images to t...   Aug 1 2006, 08:53 AM
- - punkboi   Last day to send your name to the asteroid belt is...   Sep 13 2006, 07:46 AM


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