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Posted by: jgoldader Nov 12 2007, 08:43 PM

Hi all,

Okay, I give up. I've been researching the future plans for the Voyagers for a talk I'm giving later this week. There's a nice write-up at http://voyager.jpl.nasa.gov/science/thirty.htmldiscussing the plans for the Voyager Interstellar Mission. Among the great info there are the steps that will be taken to deal with the dwindling output from the RTGs. I understand turning off the GYROs and DTR, no problem. But the last dated command (and resulting power margin change) is:

2016 - Pyro Instrumentation Power OFF (+2.4 W)

Could somebody please explain to me what this means? Does it mean turning off the pyro subsystem? What pyros would be left to fire on Voyager at this time? All I can think of is some system that could be used to permanently disable and isolate particular pieces of hardware in the event of catastrophic failure.

I've looked and looked and looked at NTRS and JPL's TRS, and have had no luck.

Thanks for any help you can give,
Jeff

ps- is there any hope of the Voyager Science and Mission Systems Handbook appearing online someday? What references I can find to it seem to suggest it's the "master manual" for Voyager, but its availability is listed as hardcopy only, in the JPL library, a couple of thousand miles from here.

Posted by: Del Palmer Nov 12 2007, 10:11 PM

There may still be unfired pyro valves in the propulsion system, which are used to isolate or pressurize parts of the system.

Posted by: stevesliva Nov 12 2007, 10:59 PM

I note that it does say pyro instrumentation turn-off.

Posted by: jgoldader Nov 13 2007, 12:42 AM

Hm... could be, as there are both primary and redundant sets of thrusters. Perhaps the pyros are to isolate the primary set and put the redundant set on line.

As another post notes, the intent seems to be to power off the instrumentation controlling the pyros. The first time I read the "pyro" line, I read "pyro" as a verb, but of course if they pyro off the instrumentation power, that more or less does it for the mission, eh? And then the next bit talks about instrument power sharing after 2016, so whatever the reference is, it is not about powering down the entire instrument suite.

Jeff