Voyager Chronology |
Voyager Chronology |
Dec 14 2007, 09:27 AM
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#1
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
I wonder if anybody has a Voyager chronology with such details as dates of all TCMs or precise times of closest approach to different moons of Jupiter back in 1979. What I've found of pre-Saturn TCMs is here:
Voyager 1 1977.09.05 Launch 1977.09.11 TCM-1 1977.09.13 TCM-1 1977.10.29 TCM-1A 1978.06? TCM-2? 1979.01.04 Jupiter Observatory Phase 1979.01.29? TCM-3 1979.02.21 TCM-4 1979.03.05 Jupiter Flyby 1979.04.09 TCM-5 ... 1980.08.22 Saturn Observatory Phase 1980.10.10-11 TCM A8 1980.11.06 TCM A9 1980.11.12 Saturn Flyby Voyager 2 1977.08.20 Launch 1977.10.11 TCM-1 1978.05.03 TCM-2 1979.04.24 Jupiter Observatory Phase 1979.06.27 TCM? 1979.07.09 Jupiter Flyby 1979.07.09 TCM? 1979.07.23 TCM? 1980? TCM B6? 1981.02.26 TCM B7 1981.06.05 Saturn Observatory Phase 1981.07.19 TCM B8 1981.08.18 TCM B9 1981.08.26 Saturn Flyby |
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Guest_PhilCo126_* |
Dec 16 2007, 04:18 PM
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#2
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Guests |
Now we just need, for each Voyager, entry and exit dates of the asteroid belt
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Dec 16 2007, 07:03 PM
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#3
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Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Ah...memories...
On 12 Nov 1980 my high school physics teacher & I went to the now-defunct Village Inn Pizza Parlor in my home town & watched the V1 Saturn encounter feed from PBS on their big-screen projection TV. We also split, uh, a few pitchers of beer (drinking age was 18 then, so I was only a couple of months shy... )...a staggering experience in all respects! -------------------- 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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Guest_PhilCo126_* |
Dec 17 2007, 03:10 PM
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#4
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Guests |
Voyager 1 & 2 passages through Jovian system
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Guest_PhilCo126_* |
Dec 17 2007, 03:15 PM
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#5
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Guests |
Voyager 1 & 2 passages through Saturn system
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Guest_PhilCo126_* |
Dec 17 2007, 03:17 PM
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#6
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Guests |
Voyager 2 fly bys of Uranus (January 1986) and Neptune (August 1989)
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Dec 17 2007, 07:55 PM
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#7
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
Now we just need, for each Voyager, entry and exit dates of the asteroid belt It's much more easy. Asteroid belt entry date is 1977 Dec 10 for both Voyagers at the distance of 2.0 AU from Sun. Voyager 1 exited the belt at 3.6 AU on 1978 Sep 08 and Voyager 2 followed her on 1978 Oct 21. Really a pity nobody knows of TCMs I missed or marked uncertain, and of Jupiter and Saturn satellites TCA times. |
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Dec 17 2007, 09:18 PM
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#8
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
Thanks for those diagrams PhilCo! I can't tell you how many times I've searched for those on the Internet. Where did you scan them from?
--Emily -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Guest_PhilCo126_* |
Dec 18 2007, 07:55 AM
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#9
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Guests |
Hello Emily,
You can check the books at the lower rightside of my weblog. Most of You know "The Voyager Neptune Travel Guide", but I prefer the 'rarer' and larger sized "The Voyager Uranus Travel Guide" (See attachments). Both can still be found at book-searches on the internet (contact me off-forum). Philip |
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Dec 18 2007, 08:21 PM
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#10
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Junior Member Group: Members Posts: 95 Joined: 5-September 07 Member No.: 3662 |
It's too bad that finding info on Voyager is so difficult. The nice folks at the Voyager project at JPL have helped me a couple of times, but even they have trouble putting their hands on some things. I'd been looking for photos of the cable harnesses entering the scan platform instruments for a model I'm building, and the Voyager project couldn't locate what I was after. I imagine the closeout photos are all in boxes in the JPL archives by now! I was grateful for the effort, I know they're doing a lot with a small crew.
Oh--the Voyager Neptune Travel Guide is available through NTRS, I believe, but not the Uranus one. It's a big PDF, but beautifully written. Also, and slightly OT, I'd love to hear from anybody who's got good info on the solid upper stages that were actually controlled by the Voyagers themselves. There's precious little on them out there on the Internet, and I haven't found anything substantial even in books about the Voyager project. You can PM me if you wish. Jeff |
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Jan 3 2008, 01:27 PM
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#11
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
I was able to found times of Jupiter flyby for Voyager 1 in UTC Earth Receive Time (some 17.7 minutes after the real event):
1979.03.05 12:42 Jupiter 1979.03.05 15:51 Io 1979.03.05 17:56 Europa 1979.03.06 02:53 Ganymede 1979.03.06 17:45 Callisto I also have a precise spacecraft time for Io flyby, 15:13:21, and two versions of Jupiter flyby time, 12:05:26 or 12:04:36. I presume that one of this time is what was seen online and another is what was calculated post-flyby from all tracking points. |
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Jan 3 2008, 01:33 PM
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#12
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
How come only 17.7 minutes? Light time should add up to more than that.
EDIT: Ahh, probably a typo, should read 37.7 minutes instead. -------------------- |
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Jan 4 2008, 03:49 PM
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#13
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
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Apr 18 2008, 09:23 AM
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#14
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
I can offer the following, need to do more research to verify timezones and SCET/ERT:
The Overtaking: 19 Dec 1977 Voyager 1 overtakes Voyager 2 Voyager 1 05 Mar 1979 (06:54) Amalthea: Amalthea flyby (distant) 05 Mar 1979 (12:05) Jupiter: Jupiter Fly-By 05 Mar 1979 (15:14) Io: Io flyby 05 Mar 1979 (18:19) Europa: Europa flyby (distant) 06 Mar 1979 (02:15) Ganymede: Ganymede flyby 06 Mar 1979 (17:08) Callisto: Callisto flyby 12 Nov 1980 (05:41) Titan: Titan flyby (targetted) 12 Nov 1980 (22:17) Tethys: Tethys flyby (distant) 12 Nov 1980 (23:46) Saturn: Saturn Fly-By 13 Nov 1980 (01:43) Mimas: Mimas flyby 13 Nov 1980 (01:51) Enceladus: Enceladus flyby (distant) 13 Nov 1980 (03:39) Dione: Dione flyby (distant) 13 Nov 1980 (06:22) Rhea: Rhea flyby 13 Nov 1980 (16:45) Hyperion: Hyperion flyby (distant) 17 Feb 1998 Voyager 1 overtakes Pioneer 10 and becomes most distant spacecraft from the sun by 2028 Reaches Heliopause in 40,000 years Passes Star AC+79 3888 (at distance of 1.6 light-years) Voyager 2 08 Jul 1979 (12:21) 214,930 km Callisto: Callisto flyby (distant) 09 Jul 1979 (07:14) 62,130 km Ganymede: Ganymede flyby 09 Jul 1979 (17:53) 205,720 km Europa: Europa flyby (distant) 09 Jul 1979 (20:01) 558,370 km Amalthea: Amalthea flyby (distant) 09 Jul 1979 (22:29) 721,883 km Jupiter: Jupiter 09 Jul 1979 (23:17) 1,129,900 km Io: Io flyby (distant) 25 Aug 1981 (09:24) 665,960 km Titan: Titan flyby (distant) 26 Aug 1981 (01:04) 502,250 km Dione: Dione flyby (distant) 26 Aug 1981 (02:34) 309,990 km Mimas: Mimas flyby (distant) 26 Aug 1981 (03:24) 161,081 km Saturn: Saturn 26 Aug 1981 (03:45) 87,140 km Enceladus: Enceladus flyby 26 Aug 1981 (06:12) 93,000 km Tethys: Tethys flyby 26 Aug 1981 (06:29) 645,280 km Rhea: Rhea flyby (distant) 24 Jan 1986 (17:59) 107,092 km Uranus: Uranus 14 Feb 1986 2.5 hrs trajectory correction maneuvre targets Voyager 2 towards Neptune 25 Aug 1989 39,800 km Triton: Triton 25 Aug 1989 (03:56) 29,216 km Neptune: Neptune by 2008 Termination shock area by 2028 Reaches Heliopause in 296,000 years Passes Sirius (at a distance of 4.3 lightyears ) -------------------- |
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Jun 19 2008, 07:02 PM
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#15
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
Thank you very much, dmuller.
I also have a precise spacecraft time for Io flyby, 15:13:21, and two versions of Jupiter flyby time, 12:05:26 or 12:04:36. I presume that one of this time is what was seen online and another is what was calculated post-flyby from all tracking points. Things proved to be even more interesting. Both are times of closest approach, spacecraft time! 12:04:36 is UTC, but 12:05:26 is ET (ephemeris time), currently known as terrestrial time (TT). In 1979, ET was 32.184 seconds ahead of TAI and UTC was 18 seconds behind TAI. |
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Jun 19 2008, 08:38 PM
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#16
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Member Group: Members Posts: 903 Joined: 30-January 05 Member No.: 162 |
I recall being very nervous about the Voyager 1 Jupiter flyby as the interesting satellite passes occurred after closest Jovian approach and I was extremely worried about radiation messing up the craft before they happened.
I managed to be in the Huntley Lodge in Montana, as I recall, for the great 1979 solar eclipse. It was a sufficient distraction to make my Voyager anxiety tolerable. Time magazine managed to cover both events in the same issue. |
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Jun 21 2008, 06:12 PM
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#17
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
I can offer the following, need to do more research to verify timezones and SCET/ERT: 12 Nov 1980 (05:41) Titan: Titan flyby (targetted) 12 Nov 1980 (22:17) Tethys: Tethys flyby (distant) 12 Nov 1980 (23:46) Saturn: Saturn Fly-By 13 Nov 1980 (01:43) Mimas: Mimas flyby 13 Nov 1980 (01:51) Enceladus: Enceladus flyby (distant) 13 Nov 1980 (03:39) Dione: Dione flyby (distant) 13 Nov 1980 (06:22) Rhea: Rhea flyby 13 Nov 1980 (16:45) Hyperion: Hyperion flyby (distant) Well, I was able to extract the sequence of Voyager 1 Saturn flyby from Voyager 1 and Voyager 2 Saturn encounter orbit determination Campbell J.K., Jacobson R.A., Riedel J.E., Synnott S.P., Taylor A.H. AIAA-1982-419 20th Aerospace Sciences Meeting, Orlando, FL, Jan 11-14, 1982, 17 p. At http://www.aiaa.org/content.cfm?pageid=406...r&gID=90384 the report is not available without payment but with a carefull googling all the encounter table may be extracted. Event - Date and time, UTC - Time relative to CA, hours - Distance Titan CA. 11/12/80 05:40:41 -18.09 6969 Enter Titan Sun-occ. 05:46:22 -17.99 Enter Titan Earth-occ. 05:47:33 -17.97 [Exit] Titan Sun-occ. 05:57:06 -17.81 Descending node 05:58:09 -17.79 1184575 Exit Titan Earth-occ. 05:59:45 -17.77 Tethys CA 22:15:52 -1.50 415855 Saturn CA* 23:45:50 0. 184497 Closest Mimas in light 11/13/80 00:37:41 +0.86 108432 Mimas CA** 01:42:32 +1.95 88996 Enter Saturn Earth-occ. 01:43:16 +1.96 Enceladus CA 01:50:36. +2.08 202796 Enter Saturn Sun-occ. 01:56:54 +2.18 Exit Saturn sun-occ. 02:37:24 +2.86 Exit Saturn Earth-occ. 03:10:35 +3.41 Enter Ring Earth-occ. 03:19:40 +3.56 Closest Dione in light 03:28:13 +3.71 161543 [Exit] Ring Earth-occ. 03:35:09 +3.82 Dione CA*** 03:39:00 +3.89 161285 Ascending node 04:20:06 +4.57 377902 Rhea CA 06:21:13 +6.59 72797 Hyperion CA 16:44:01 +16.97 897277 CA = closest approach *One-way light time = 01 24 47 **Mimas is in darkness at CA ***Dione is in darkness at CA |
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Jun 24 2008, 08:37 PM
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#18
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
Voyager 2 25 Aug 1981 (09:24) 665,960 km Titan: Titan flyby (distant) 26 Aug 1981 (01:04) 502,250 km Dione: Dione flyby (distant) 26 Aug 1981 (02:34) 309,990 km Mimas: Mimas flyby (distant) 26 Aug 1981 (03:24) 161,081 km Saturn: Saturn 26 Aug 1981 (03:45) 87,140 km Enceladus: Enceladus flyby 26 Aug 1981 (06:12) 93,000 km Tethys: Tethys flyby 26 Aug 1981 (06:29) 645,280 km Rhea: Rhea flyby (distant) Again I was able to extract Voyager 2 Saturn visit times from the article by Campbell, Jacobson et al. Date and time, UTC SCET -- Time from Saturn CA -- Event -- Distance, km 1981.08.23 01:26:56.5 -03 01:57:11 Iapetus 909070 1981.08.25 01:25:25.8 -01 01:58:42 Hyperion 470840 1981.08.25 09:37:46.3 -00 17:46:21 Titan 665960 1981.08.25 22:57:33.2 -00 04:26:35 SXII Helene (1980 S6) 318200 1981.08.26 01:04:31.8 -00 02:19:36 Dione 502250 1981.08.26 02:22:16.8 -00 01:01:51 SXIV Calypso (1980 S25) 153518 1981.08.26 02:34:26.X -00 00:49:41 Mimas 309990 1981.08.26 03:08:29.4 -00 00:15:38 SXVII Prometheus (1980 S28) 287170 1981.08.26 03:19:17.5 -00 00:04:50 SXV Pandora (1980 S26) 107000 1981.08.26 03:24:07.8 00 00:00:00 Saturn 1981.08.26 03:33:02.4 +00 00:08:55 SXVI Atlas (1980 S27) 246590 1981.08.26 03:45:16.1 +00 00:21:08 Enceladus 87140 1981.08.26 03:50:03.6 +00 00:25:56 SX Janus (1980 S1) 222760 1981.08.26 04:00:24.6 +00 00:36:17 Earth occult enter Saturn? 166133 1981.08.26 04:05:55.8 +00 00:41:48 SXI Epimetheus (1980 S3) 147010 1981.08.26 04:08:12.1 +00 00:44:04 Sun (umbra) occult enter Saturn 1981.08.26 05:34:36.9 +00 02:10:29 Earth occult leave Saturn 215762 1981.08.26 05:44:56.s +00 02:20:21 Sun (umbra) occult leave Saturn 223334 1981.08.26 06:02:46.7 +00 02:38:39 SXIII Telesto (1980 S13) 284400 1981.08.26 06:12:30.2 +00 02:48:22 Tethys 93000 1981.08.26 06:28:48.4 +00 03:04:41 Rhea 645280 1981.09.05 01:22:33.5 +09 21:58:26 Phoebe 2073640 Notes: 1. Two or more lines for rings crossing were not discernible. 2. Numbers cross-checked against the Saturn CA time. 3. Current names an designations for small satellite discovered in 1979-1980 are used. 4. Don't know why this distance to Phoebe was there in the table. 5. Current estimate for Saturn CA seems to be 03:24:05. |
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Jun 26 2008, 09:34 PM
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#19
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Member Group: Members Posts: 655 Joined: 22-January 06 Member No.: 655 |
I never cease to be amazed at the quality of the initial reconnaisance of the Saturn system by the two Voyagers. The amount of data gathered by the two craft, which between them spent less than two weeks within Iapetus' orbit is nothing short of astonishing.
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Aug 20 2008, 11:12 PM
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#20
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Senior Member Group: Admin Posts: 3108 Joined: 21-December 05 From: Canberra, Australia Member No.: 615 |
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May 15 2009, 11:36 AM
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#21
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Junior Member Group: Members Posts: 39 Joined: 26-March 09 From: Cornwall Member No.: 4697 |
A few more Voyager 2 dates, source is a diagram in Spaceflight, Nov 81:
1979-07-23 TCM6 1981-07-31 Start Far Encounter 1 1981-08-11 Start Far Encounter 2 1981-08-25 Start Near Encounter (CA-16 h) 1981-08-27 End Near Encounter (CA+28 h) 1981-09-28 End Post Encounter 1981-09-29 TCM10 |
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Jul 22 2009, 01:21 PM
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#22
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Junior Member Group: Members Posts: 45 Joined: 18-July 05 Member No.: 439 |
--- Unnecessary quoting removed! Mod. ---
Thank you very much, qwiz. |
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Aug 22 2012, 10:53 PM
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#23
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Member Group: Members Posts: 241 Joined: 16-May 06 From: Geneva, Switzerland Member No.: 773 |
35 years of flight !! Happy Anniversary Voyager 2 !
http://voyager.jpl.nasa.gov/news/voyager_35.html |
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Jan 22 2014, 11:45 PM
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#24
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Founder Group: Chairman Posts: 14432 Joined: 8-February 04 Member No.: 1 |
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Jan 23 2014, 12:45 AM
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#25
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Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Yeah, orbital motion & points of reference will mess you up every time.
-------------------- 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 8 2014, 03:39 PM
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#26
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Member Group: Members Posts: 102 Joined: 8-August 12 Member No.: 6511 |
That raises a question: has anyone worked out exactly when Voyager will hit the mark of 20 billion kilometers from Earth? (It's currently 19.033 billion.) A quick BOTE calculation gives December 2015, but Earth's orbital motion makes that a very rough estimate.
I know 20 billion is just a number. But, dang, it's a big number. Doug M. |
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Feb 10 2014, 09:09 AM
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#27
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Senior Member Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 |
According to Horizons it will be on 4th November 2015, at 05:22 UTC in the Eastern US, 05:23 in the UK and Western US, three minutes later still in Australia.
-------------------- |
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Feb 12 2014, 09:42 AM
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#28
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Member Group: Members Posts: 102 Joined: 8-August 12 Member No.: 6511 |
Well, mark our calendars! Thank you, James.
Doug M. |
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Dec 30 2014, 03:25 PM
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#29
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Member Group: Members Posts: 102 Joined: 8-August 12 Member No.: 6511 |
So the official NASA extended mission plan for Voyager 1, last updated in June 2014, tells us that this is the year its gyroscope will be shut down: "Discontinue gyro operations (+14.4 W steady state, +3.6 W turn on transient and maneuver) - 2015; TBD. This power load reduction step is currently sequenced to occur on DOY 350, 2015 but could be changed if the RTG output is better than predicted."
I assume DOY 350 would be ooa December 16, 2015... Okay, so does anyone know anything more? Is the RTG output about as expected? And what consequences will there be from turning off the gyroscope? Doug M. |
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Dec 31 2014, 10:59 PM
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#30
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Junior Member Group: Members Posts: 95 Joined: 5-September 07 Member No.: 3662 |
So the official NASA extended mission plan for Voyager 1, last updated in June 2014, tells us that this is the year its gyroscope will be shut down: "Discontinue gyro operations (+14.4 W steady state, +3.6 W turn on transient and maneuver) - 2015; TBD. This power load reduction step is currently sequenced to occur on DOY 350, 2015 but could be changed if the RTG output is better than predicted." I assume DOY 350 would be ooa December 16, 2015... Okay, so does anyone know anything more? Is the RTG output about as expected? And what consequences will there be from turning off the gyroscope? Doug M. AFAIK, the RTG output hasn't really changed from predictions. The exponential decay of the plutonium and degradation of the thermocouples are both well understood. Unless something in the power system fails, the wattage should be accurately predictable for the duration of the mission. But two things come immediately to mind with shutting down the gyros. First, the periodic antenna repointings will require hydrazine when the gyros are powered down. Voyager 1 had 18 kg of hydrazine left as of September 19, and typical consumption is about 5-6 grams per week. I don't know how much a repointing will cost, or how often it needs to be done (I looked at the weekly 2014 reports, which are current up to September 19, and no repointings were obvious for either V1 or V2 during the year). Science observations on V1 (rolling the spacecraft for particles/fields) take 100-400 grams, it seems, so I'd guesstimate that much for a repointing. But if it's done annually or less frequently, there should be enough hydrazine until the RTGs finally run too low to keep the spacecraft operating. Second, the gyros make heat. It's amazing that the spacecraft are able to function in the cold. Without heaters and insulation, they'd probably be down to 30-40K by now. It wouldn't be a terrible surprise to me if at some point, an important piece just got too cold to work. (E.g., the hydrazine freezes in the fuel lines, or a piece of electronics fails or something.) I remember listening to Jay Barbree report the launch of one of the Voyagers in 1977, and was glued to the TV during the flybys. I sure hope to see Voyager 2 break through into interstellar space before either it or I shut down. That both V1 and V2 are still working is virtually miraculous, and a testament to the dedication and talent of the people who designed, built, and operate them. |
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Jan 5 2016, 08:58 PM
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#31
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Newbie Group: Members Posts: 2 Joined: 19-July 15 Member No.: 7607 |
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Jan 16 2016, 07:54 AM
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#32
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Member Group: Members Posts: 102 Joined: 8-August 12 Member No.: 6511 |
So, do we know whether the gyros shut down on schedule or not?
Doug M. |
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Jan 16 2016, 07:55 AM
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#33
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Member Group: Members Posts: 102 Joined: 8-August 12 Member No.: 6511 |
According to the odometer at voyager.jpl.nasa.gov/where/, Voyager 1 reached 20 billion km from the Sun today at 21:34 Central European Time (20:34 UT, or 12:34 PM Pacific Time). Woo hoo! Another milestone that passed unnoticed last year: at 38 years of age, the two Voyager missions are now older than the average American (37). Doug M. |
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Dec 10 2019, 09:44 PM
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#34
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Junior Member Group: Members Posts: 89 Joined: 27-August 05 From: Eccentric Mars orbit Member No.: 477 |
I have been searching for this kind of information myself, and have come up with an almost-comprehensive list of TCMs for the spacecraft. The most detailed information comes from a series of papers on the reconstruction of the trajectories in the ICRF frame, by Robert Jacobson at JPL. A lot of the rest comes from the Voyager mission status bulletins, travel guides, and some of the details come from this very thread!
In the later part of the mission (definitely after the Saturn encounter, but maybe before that), they started calling all TCMs for Voyager 1, TCM-Ax, where the x is a serial number for the planned maneuvers. If a maneuver is cancelled, they don't reuse the serial number. All TCMs for Voyager 2 are TCM-Bx. References: MSBxx - Mission Status Bulletin, from the Planetary Society KF Voyager - Voyager Orbit Determination at Jupiter Planet ICRF - one of the series of papers by Jacobson et al:
Travel guides: Press Conferences (Yes, those have some information as well) Kernels are all on JPL NAIF CODE Voyager 1 Number Date In Kernel? Reference Notes A1 1977-09-11/13 SuperTraj MSB09,MSB14 Voyager 1 executed its first TCM in two parts on September 11 and 13. Both burns were about 20% underspeed, with the first achieving 2.45m/s and the second, 10.11m/s (Total 13.56m/s if both were in the same direction). The kernel available at NAIF suggests one TCM on 1977-09-13T09:13:58/10:14:13 (All times in kernels are in Spice ET), averaging about 4.06mm/s^2 over 1 hour, for a total DV of about 14.6m/s which is a little bit high for the whole TCM. The kernel claims to be a patched conic curve fit, but this suggests that there is more to it. Also, the fact that the kernel comes as modified difference lines suggests that it is integrated. A1A 1977-10-29 No MSB11, MSB14 Voyager 1 executed its second TCM on October 29. This was a cleanup of the TCM1 inaccuracy. This TCM does not appear to be recorded in the kernel. A2 1978-06 Cancelled? A3 1979-01-29 No MSB34, KF Voyager DV designed 4.146, achieved 4.208, DB.R -1725km, DB.T 13125km, DT +14m A4 1979-02-21 03:58:45 JUP230 KF Voyager AAS-02-157 DV designed 0.586, achieved 0.594, DB.R +710km, DB.T -100km, DT -14s. Kernel shows an impulse of 0.52m/s at 03:59:45. Table in AAS-02-157 shows reconstructed magnitude -107.955mm/s X, 303.418Y, -374.170Z (total magnitude 493.68mm/s) A5 1979-04-09 MSB52 Voyager 1 executed a very large TCM as described in the Voyager 2 pre-flyby news conference, which occurred on Wednesday, May 30, 1979 at 10:30am in Washington, DC: Since we last spoke to you, there have been a couple of spacecraft events I want to discuss. First, Voyager 1 performed its large trajectory correction maneuver on April 9. That was about a 7.3 hour burn of the thrusters that imparted a delta-V of something like 64 meters per second; used up about 30 kilograms of our propellant and, at this time, we have left about 55 kilograms of propellant. This is a post-Jupiter maneuver, which occurred at about 35 days after the Jupiter closest approach. A6 Cancelled A7 1979-12-07 MSB52 A8 1980-10-10 19:09:51/23:56 TDB SAT337 MSB52,MSB54,Saturn ICRF "Voyager 1 will perform a planned trajectory correction maneuver on October 10[, 1980]. The thrusters will fire briefly to accelerate the spacecraft about 2 meters per second and to change its course slightly. Withou this approximately 13.7-minute burn, the spacecraft would be on a collision course with Titan, Saturn's largest satellite." Saturn ICRF reconstruction shows -1360.092mm/s X, 1183.900Y, -274.575Z (total magnitude 1823.970mm/s). Kernel shows acceleration of about 2.07mm/s for 14m05s (845s) for a deltaV of about 1.749m/s A9 1980-11-07 03:39:58 TDB No MSB52,MSB54, Saturn ICRF "A final course correction is scheduled for November 7[, 1980] if needed to "fine-tune" the flight path." Saturn ICRF shows -550.847mm/s X, 1229.873Y, -640.546Z (total magnitude 1492.09mm/s) Voyager 2 Number Date In Kernel? Reference Notes B1 1977-10-11 SuperTraj MSB10, MSB11 Voyager 2 executed its first TCM on October 11. Based on experience from Voyager 1, the plan was updated and the desired correction was achieved to within 1%. Once again, the kernel captured this. The TCM as recorded took place on 1977-Oct-12T01:47:07/02:29:08, so shorter than Voyager 1. The duration of the burn is 00:42:01 or 2521 seconds. The average acceleration was about 3.93mm/s^2, so the delta-v was about 9.91m/s. The aimpoint at Jupiter was changed, such that closest approach to Ganymede was changed from 55000km to 60000km. Also, the planned Post-Jupiter TCM was changed from 70 days after closest approach to 11 days after. This was expected to save 8.6kg of propellant. B2 1978-05-03 No MSB19, MSB20 203 seconds, 0.615m/s B3 1979-05-25 Voyager 2 executed a small TCM as described in the Voyager 1 pre-flyby news conference, which occurred on Wednesday, May 30, 1979 at 10:30am in Washington, DC: Voyager 2 last Friday [May 25] performed a minor trajectory correction maneuver to improve the aiming at Jupiter. That was just a small, about a 1 1/2 meter per second adjustment in the velocity. It is now on a good trajectory for Jupiter which, of course, it will reach on July 9. B4 1979-06-27 10:09:09 Jupiter ICRF -563.738X, 522.016Y 29.424Z B5 1979-07-10 00:39:39 Jupiter ICRF 8723.415X, -8807.558Y, -3908.574Z. This is during the Io Volcano Watch, and several images from the volcano watch were taken during the burn, so they were confident that the TCM thrusters are smooth enough to take data while burning. B6 1979-07-23 16:09:50 Jupiter ICRF -166.348X, 607.505Y, 500.864Z B7 1981-02-26 Unmannedspaceflight.com post B8 1981-07-19 11:16:25 Saturn ICRF -469.649X, 882.511Y, 648.463Z B9 1981-08-18 21:26:16 Saturn ICRF -230.733X, 1205.871Y, -534.300Z B10 1981-09-29 [1] B11 B12 B13 1985-12-23 Uranus Travel Guide B14 1986-01-19 Uranus Travel Guide B15 1986-02-14 Uranus Travel Guide, Unmannedspaceflight.com post B17 1989-04-20 16:19:46 Neptune ICRF 91.925X, -339.117Y, -10.428Z B18 1989-08-01 12:55:18 Voyager Neptune Travel Guide, Neptune ICRF -335.093X, -850.755Y, -161.348Z B19 (N-9d18h) Voyager Neptune Travel Guide, Neptune ICRF Cancelled "The Navigation Team estimates that there is about a 25 percent chance that TCM B19 will not be needed, given that TCM B20 remains to remove some position errors B20 1989-08-21 12:48:06 Voyager Neptune Travel Guide, Neptune ICRF -477.544mm/sX, -8.441Y, -12.920Z |
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