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Voyager Chronology
Řyvind G
post Jan 5 2016, 08:58 PM
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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). I'm sharing a PC screenshot from the moment. (Numbers of interest are enlarged at lower right.)
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Doug M.
post Jan 16 2016, 07:54 AM
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So, do we know whether the gyros shut down on schedule or not?


Doug M.
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Doug M.
post Jan 16 2016, 07:55 AM
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QUOTE (Řyvind G @ Jan 5 2016, 10:58 PM) *
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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kwan3217
post Dec 10 2019, 09:44 PM
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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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