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I couldn't find a good tag for the disabling, neutralization, or passivation of a spacecraft at EOM, or some subsystem thereof when no longer needed, when posting the question Have all of InSight's engines/thrusters been permanently disabled now that it has landed?. Any thoughts?

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currently has 17 questions.

The description is currently

Questions related to extending the lifetime, and determining when the useful period of a satellite has ended.

In addition to what is written above in this meta question, @uhoh makes a good point that there is no good tag for "EOM-associated activities. EOM is a moment in time, or a system status."

I also think the current definition is too narrowly-written for satellites. Landers and rovers should be fair game.

I am proposing changing the definition of to

Questions related to the lifetime or end-of-mission of a spacecraft. This may include determining when the useful period has ended, extending the lifetime, and safely disabling/passivating/disposing it.

I welcome concerns or improvements to this proposed definition. In particular, we want this distinctive from the tag, but I'm not sure how to word that.

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I'd go for . While a lot of it occurs at EoM, it is a separate process, and could occur to subsystems long before EoM of an object -- e.g Skylon venting it's launch tanks after achieving orbit.

As a downside, it has a different meaning in chemistry, and that meaning may apply to aspects of plumbing.

The early Apollo Applications Program documents talked of passivating between launch and commencement of orbital operations

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  • $\begingroup$ Passivization, to my mind, is a subset of end of mission activities. $\endgroup$ – Russell Borogove Dec 3 '18 at 13:10
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    $\begingroup$ I agree that is where most passivation occurs, @RussellBorogove, but not the only place. Arguably, the subsystems to which it occurs have reached the end of their mission. $\endgroup$ – JCRM Dec 3 '18 at 14:05
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    $\begingroup$ Passivization also refers to material handling processes during construction of spacecraft (among other things), so it could lead to some ambiguity. $\endgroup$ – Tristan Dec 4 '18 at 17:45
  • $\begingroup$ That was what I was referring to with "plumbing" @Tristan $\endgroup$ – JCRM Dec 5 '18 at 9:38
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    $\begingroup$ Perhaps "safing" might be more relevant? Passivization is also used on structural elements. $\endgroup$ – Tristan Dec 5 '18 at 15:45
  • $\begingroup$ Feel free to suggest it in an answer @Tristan -- I'd use it in a reversible context though, pre-launch. $\endgroup$ – JCRM Dec 5 '18 at 16:50
  • $\begingroup$ just asked: What is “propulsive passivation” and why will the SpaceX STP-2 mission do it? $\endgroup$ – uhoh Apr 21 '19 at 1:55
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    $\begingroup$ @uhoh "Passivation" is indeed a part of en of life activities and does cover the objectives of he question as you've written it. It is also the term used by the IADC (Inter-Agency Debris Co-ordination Committee) in the same role. $\endgroup$ – Puffin Apr 21 '19 at 8:37
  • $\begingroup$ @Puffin how do you feel about the "...or some subsystem..." aspect of the question? Insight's thrusters have (most likely) been permanently deactivated and propellant vented, but the lander as a whole still quite operational. Can we say the thrusters have been passivated? $\endgroup$ – uhoh Apr 21 '19 at 9:34
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    $\begingroup$ @uhoh Yes, in principle that makes sense to use the language this way. $\endgroup$ – Puffin Apr 21 '19 at 15:27
  • $\begingroup$ let's see how it flies $\endgroup$ – uhoh Feb 1 at 0:56
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    $\begingroup$ "Safing" to me has heavy implications of ordnance/explosives: safing pins on ejection seats, safe-and-arm devices on SRBs, etc. $\endgroup$ – Organic Marble Feb 20 '19 at 1:39
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    $\begingroup$ "putting into safe mode" was the term used in the End of Mission email so "safing" would apply. However satellites do go into (and come out of) Safe Mode potentially multiple times due to fault events so it doesn't convey the finality that may be wanted in this case at the end of a mission. $\endgroup$ – astrosnapper Feb 1 at 1:11

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