I've just read in Eshleman et al 1977 Radio Science Investigations with Voyager that the voyagers have:

...a novel attitude-control thruster configuration that minimizes accelerations along the Earth-spacecraft line-of-sight;

I am guessing that the goal would be to minimize any tiny amount of delta-v that would affect doppler measurements of velocity, since there is so much science available in these precision measurements.

Does this just mean that the "novel attitude-control thruster configuration" is designed to balance the impulse from the thrusters used so that only torque is applied about the spacecraft center of mass? If so, how was this novel minimization accomplished?

If it doesn't, then what does it mean?

  • $\begingroup$ I think the answer to your question is on page 258 of this paper, but I don't understand it well enough to write an answer: users.cecs.anu.edu.au/~Jonghyuk.Kim/teaching/KF%20Voyager.pdf $\endgroup$ – Organic Marble Jan 21 '19 at 14:44
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    $\begingroup$ I've done a fairly extensive search, but can't find any information on how the thrusters are installed. Despite the paper referenced by @OrganicMarble I've found several texts that say the thrusters are operated in pairs, but offer no detail beyond that. That paper does not go into detail on thruster configuration either. $\endgroup$ – Hobbes Feb 7 '19 at 12:09
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    $\begingroup$ The available diagrams show where the thruster groups are, but don't have enough resolution to show in which direction the nozzles are pointed. $\endgroup$ – Hobbes Feb 7 '19 at 13:33
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    $\begingroup$ The Voyager Backgrounder ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19810001583.pdf and all other references I've found say that there are 12 jets in two systems of 6, only one system is used at a time. Now if you only have 6 jets, they obviously can't fire in pairs (other than in the trivial sense that one fires to start a motion and the opposing one fires to stop it) because you only have 1 jet / direction / axis. $\endgroup$ – Organic Marble Feb 8 '19 at 3:38
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    $\begingroup$ Ah. Nice job! I always forget to look at my memory joggers :( $\endgroup$ – Organic Marble Feb 14 '19 at 3:52

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