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What's Up With Ulysses?, alive? dead? cancelled soon?
deglr6328
post Sep 27 2005, 04:05 AM
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What is up with the tiny Ulysses spacecraft that was launched in 1990 to study the solar whatever at high lattitudes? Last I heard it was in danger of dying because the RTG power was running low and at aphelion there was a risk of the hydrazine freezing/exploding in its propulsion system. Well that was like a year ago and I haven't heard anything since. It looks like it should've passed aphelion by now and should be out of danger.....

Its been going up there for over a full solar cycle, is it one of the missions on the chopping block because of the new humans on moon/mars thing?
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nprev
post Feb 11 2007, 08:17 PM
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I agree with ustrax; the longevity of this spacecraft (and others) is astounding. These are arguably among the most complex devices ever built, yet without hands-on maintenance, periodic overhauls, etc., they just keep going. Wonder if the space agencies might be interested in building a few cars on the side... cool.gif

All that aside, how much longer can Ulysses keep going given this new power conservation strategy? Also, is there any possibility that it will re-encounter Jupiter at some point?


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Paolo
post Feb 11 2007, 08:44 PM
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QUOTE (nprev @ Feb 11 2007, 09:17 PM) *
Also, is there any possibility that it will re-encounter Jupiter at some point?


Back when I was in university, a dozen of years ago I played with simulating Ulysses' orbit. In that occasion I "discovered" the second flyby of 2003.
Ulysses crosses Jupiter's orbit every 6.5 years, and approaches it every 13 years, but IIRC, the encounter distance is increasing and there will be no more flybys during all of the 21st century.
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IM4
post Feb 23 2008, 01:23 PM
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QUOTE (Paolo @ Feb 11 2007, 08:44 PM) *
Back when I was in university, a dozen of years ago I played with simulating Ulysses' orbit. In that occasion I "discovered" the second flyby of 2003.
Ulysses crosses Jupiter's orbit every 6.5 years, and approaches it every 13 years, but IIRC, the encounter distance is increasing and there will be no more flybys during all of the 21st century.

I explored Ulysses orbit evolution with JPL HORIZONS system. Here are some interesting encounters till the end of XXI century:
CODE
          Date (CT)       Body  CA Dist      Vrel
  ----------------------  -----  --------  ------
  A.D. 1992 Feb 08.78380  Juptr  0.006795  20.895
  A.D. 2004 Feb 04.98546  Juptr  0.804396  13.984
  A.D. 2086 Nov 13.65625  Juptr  0.780194  14.070
  A.D. 2095 Nov 01.78213  Mars   0.056797  37.722
  A.D. 2098 Nov 07.59152  Juptr  0.004053  24.594

November 7, 2098 Ulysses will be kicked out of the Solar system by Jupiter's gravity. Spacecraft's final trajectory will be highly hyperbolic (eccentricity~1.42), so it will be travelling very fast and one day, thousands years from now, Ulysses will reach some star.
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ugordan
post Feb 26 2008, 09:40 AM
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QUOTE (IM4 @ Feb 23 2008, 02:23 PM) *
November 7, 2098 Ulysses will be kicked out of the Solar system by Jupiter's gravity. Spacecraft's final trajectory will be highly hyperbolic (eccentricity~1.42), so it will be travelling very fast and one day, thousands years from now, Ulysses will reach some star.

I'm wondering how accurate HORIZONS data can possibly be for such distant dates. There has to be a number of unmodelled factors affecting orbital evolution of the spacecraft that the system doesn't take into account such as solar radiation pressure, slow outgassing from the spacecraft, etc. These will, given enough time, measurably perturb the orbit and I'm wondering what the real flyby distance and slingshot effect will be in 2098. Even tiny perturbations now can lead to large deviations in the future predicted passes.

I wouldn't put my hand into the fire and say Ulysses is heading out of the solar system, let alone heading out on a highly hyperbolic trajectory. Move the closest approach point to Jupiter by a million km in one direction and it could end up being decelerated by Jupiter instead.

EDIT: To give a sense of what I'm talking about, consider Jupiter's orbital velocity is 13 km/s and so it needs some 21 hours to cross a million kilometers. If Ulysses is early in its orbit by a mere 20 hours at the time of the 2098 flyby, the outcome could be radically different. A 20 hour cumulative in 90 years is really not much, especially since weak forces like light pressure tend to not change orbits much, but change their circumference a bit, which then brings timing differences that accumulate over time.


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Posts in this topic
- deglr6328   What's Up With Ulysses?   Sep 27 2005, 04:05 AM
- - Myran   Yes I havnt heard much news about Ulysses since it...   Sep 27 2005, 10:35 AM
- - djellison   http://ulysses-ops.jpl.esa.int/ulsfct/opssumm.html...   Sep 27 2005, 10:48 AM
- - deglr6328   Hmmm looks like alot of the instruments are switch...   Sep 27 2005, 06:22 PM
|- - ynyralmaen   QUOTE (deglr6328 @ Sep 27 2005, 08:22 PM)Hmmm...   Sep 28 2005, 08:23 AM
|- - ljk4-1   Fifteen years after its launch, the grand ESA/NASA...   Oct 6 2005, 02:42 PM
- - SigurRosFan   Ulysses 15th Anniversary Video: http://www.jpl.na...   Oct 9 2005, 01:16 PM
- - deglr6328   Neat video. Does anyone know how to unlock the eas...   Oct 9 2005, 06:01 PM
|- - tfisher   QUOTE (deglr6328 @ Oct 9 2005, 02:01 PM)Does ...   Oct 9 2005, 06:26 PM
- - deglr6328   oh. well that's not very exciting is it.   Oct 9 2005, 07:12 PM
- - Rakhir   Ulysses embarks on third set of polar passes http...   Nov 17 2006, 04:47 PM
|- - The Messenger   QUOTE (Rakhir @ Nov 17 2006, 09:47 AM) Ul...   Nov 27 2006, 09:48 PM
|- - ustrax   For those interested I've posted at the spaceu...   Jan 29 2007, 03:29 PM
- - remcook   ustrax: interesting. But what's up with the mi...   Jan 29 2007, 03:52 PM
|- - ustrax   QUOTE (remcook @ Jan 29 2007, 03:52 PM) u...   Jan 29 2007, 03:59 PM
- - remcook   ah I see now.   Jan 29 2007, 04:38 PM
|- - ustrax   There goes Ulysses...again... I really enjoy Dr....   Feb 7 2007, 01:47 PM
|- - peter59   QUOTE (ustrax @ Feb 7 2007, 02:47 PM) ...   Feb 23 2008, 09:14 AM
|- - tedstryk   QUOTE (peter59 @ Feb 23 2008, 09:14 AM) I...   Feb 25 2008, 03:08 PM
- - AlexBlackwell   Ulysses scores a hat-trick ESA 7 February 2007   Feb 7 2007, 05:34 PM
- - nprev   I agree with ustrax; the longevity of this spacecr...   Feb 11 2007, 08:17 PM
|- - Paolo   QUOTE (nprev @ Feb 11 2007, 09:17 PM) Als...   Feb 11 2007, 08:44 PM
||- - IM4   QUOTE (Paolo @ Feb 11 2007, 08:44 PM) Bac...   Feb 23 2008, 01:23 PM
||- - ugordan   QUOTE (IM4 @ Feb 23 2008, 02:23 PM) Novem...   Feb 26 2008, 09:40 AM
||- - tedstryk   For most of that time it should be away from major...   Feb 26 2008, 03:46 PM
|- - Jeff7   QUOTE (nprev @ Feb 11 2007, 03:17 PM) I a...   Feb 13 2007, 03:36 AM
|- - centsworth_II   QUOTE (Jeff7 @ Feb 12 2007, 10:36 PM) A c...   Feb 13 2007, 03:56 AM
|- - Jeff7   QUOTE (centsworth_II @ Feb 12 2007, 10:56...   Feb 21 2007, 04:06 AM
- - Littlebit   Ulysses Update: http://www.spaceref.com/news/view...   Feb 20 2007, 02:54 PM
- - dvandorn   This is the old argument they went through when th...   Feb 21 2007, 03:43 PM
|- - David   QUOTE (dvandorn @ Feb 21 2007, 03:43 PM) ...   Feb 22 2007, 02:19 AM
||- - ustrax   We'll miss you...   Feb 22 2008, 02:56 PM
|- - ilbasso   QUOTE (dvandorn @ Feb 21 2007, 10:43 AM) ...   Feb 22 2008, 04:23 PM
- - djellison   Well - there's a lot of science to be had from...   Feb 22 2008, 03:37 PM
- - stevesliva   You know, for all the flack that ESA's press f...   Feb 22 2008, 06:07 PM
- - djellison   I'm hoping that this is how MER goes out - wit...   Feb 22 2008, 06:41 PM
- - deglr6328   Looks like my old thread was just a few years too ...   Feb 23 2008, 08:40 PM
- - djellison   Basically, yes. That's my understanding of it...   Feb 23 2008, 09:00 PM
- - edstrick   Remember that Ulysses needs to periodically re-ori...   Feb 24 2008, 08:28 AM
|- - mcaplinger   QUOTE (edstrick @ Feb 24 2008, 12:28 AM) ...   Feb 24 2008, 04:21 PM
- - robspace54   Thermal Constraints of the Reaction Control Subsys...   Feb 25 2008, 09:42 PM
|- - tedstryk   I know that during the Jupiter Distant Encounter i...   Feb 26 2008, 05:35 AM
- - IM4   Yep, I made a stupid mistake. Or even two. As for...   Feb 26 2008, 04:26 PM
- - robspace54   This paper from 2004 tells us that the "freez...   Feb 27 2008, 06:48 PM
- - mcaplinger   From Emily's blog on planetary.org about Ulyss...   Mar 15 2008, 02:05 AM
- - Mongo   There are some fine lines in Tennyson's poem U...   Mar 15 2008, 02:15 AM
- - elakdawalla   Thanks for the tip, Mike. Haven't gotten to b...   Mar 15 2008, 03:44 AM
- - Paolo   From Dante's Commedia (Inferno XXVI): 'O ...   Mar 15 2008, 09:31 PM
|- - dilo   QUOTE (Paolo @ Mar 15 2008, 10:31 PM) fat...   Mar 16 2008, 08:25 AM
- - jamescanvin   Looks like news regarding the death of Ulysses may...   Apr 16 2008, 09:52 AM
- - GravityWaves   After more than 17 years relentlessly exploring th...   Jun 5 2008, 04:16 PM
- - Paolo   From the "programmes in progress" sectio...   Jun 8 2008, 09:34 AM
- - Paolo   Today at ESA Headquarters, the Ulysses Legacy pres...   Jun 12 2008, 07:09 PM
|- - robspace54   Today is June 30th, so folks, say goodbye to old U...   Jun 30 2008, 08:40 PM
|- - tedstryk   QUOTE (robspace54 @ Jun 30 2008, 09:40 PM...   Jul 1 2008, 02:23 PM
- - nprev   A sad day to be sure, but also a happy one. Could ...   Jul 1 2008, 03:34 PM
- - ynyralmaen   Yes, a hugely successful mission... many congrats ...   Jul 1 2008, 07:39 PM
- - Rakhir   Ulysses hanging on valiantly http://www.esa.int/es...   Jul 3 2008, 09:49 PM
|- - ustrax   Humm...changes in the solar system?...any idea of ...   Sep 22 2008, 10:02 AM
- - tanjent   That should indeed be interesting. I assume the ph...   Sep 22 2008, 12:59 PM
|- - ustrax   I'm starting to get the chills...Can it be rel...   Sep 22 2008, 04:06 PM
- - Del Palmer   Don't fret, a new sunspot just appeared today.   Sep 22 2008, 10:32 PM
- - Del Palmer   Ulysses finds that the solar wind pressure and mag...   Sep 23 2008, 05:47 PM
|- - SolarSystemRubble   QUOTE (Del Palmer @ Sep 23 2008, 12:47 PM...   Sep 23 2008, 06:21 PM
|- - Sunspot   QUOTE (SolarSystemRubble @ Sep 23 2008, 07...   Sep 24 2008, 07:11 AM
- - imipak   Climatology's been ruled off-topic for UMSF I...   Sep 24 2008, 09:27 AM
- - Paolo   There are status updates on Ulysses at http://ulys...   Jan 4 2009, 11:06 AM
- - Paolo   The latest mission status. Ulysses is still alive...   Mar 17 2009, 04:54 PM
- - elakdawalla   I was in JPL's Space Flight Operations Facilit...   Mar 17 2009, 06:44 PM
|- - tedstryk   I would love it if it picked up one last comet tai...   Mar 18 2009, 01:34 PM
|- - G0DXS   The day has finally come! The last day for mis...   Jun 24 2009, 04:15 AM
|- - robspace54   The little spacecraft that could... and DID from O...   Jun 27 2009, 06:53 PM
- - dmuller   Man I saw the launch live at Cape Canaveral. I was...   Jun 29 2009, 11:33 PM
- - dmuller   From the mission ops blog: QUOTE UTC Timestamp: 2...   Jun 29 2009, 11:36 PM
- - Astro0   While Goldstone is down, the torch has been passed...   Jun 30 2009, 06:58 AM
|- - ustrax   "The thunder and the sunshine, and opposed Fr...   Jun 30 2009, 07:45 AM
- - dmuller   Ulysses has just been switched off in good config ...   Jun 30 2009, 08:21 PM
- - cbcnasa   Thank you and farewell Ulysses   Jul 2 2009, 04:54 PM


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