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I'm curious about rocket dashboards. Separation events are big things and they depend on pyro bolts detonating and linear charges or pneumatic pushers firing immediately afterward. There must be indicators for these events in case something goes awry.

Would those indicators be the sort that illuminate when an event is detected? Would they illuminate only while the event is taking place, or would they stay permanently illuminated afterward---or might they start out illuminated and turn off once the pyros fire so they don't create distractions for the crew?

...Or would the display be of a sort in which none of these questions make sense?

Huge thanks if you can clarify!

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  • $\begingroup$ One question per post is best. $\endgroup$
    – uhoh
    Jan 6, 2021 at 5:08
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    $\begingroup$ Thanks, uhoh, that makes sense, actually. $\endgroup$
    – user36480
    Jan 6, 2021 at 5:22
  • $\begingroup$ looks much better, thanks! $\endgroup$
    – uhoh
    Jan 6, 2021 at 7:20
  • $\begingroup$ Is this about panels used by ground control, or by crew in manned spacecraft? The Shuttle and Apollo are both very well documented. $\endgroup$
    – ikrase
    Jan 6, 2021 at 10:20

1 Answer 1

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Shuttle:

The cockpit display indications for separation events were rather subtle. This is presumably because visual/physiological cues were available. Some fields on the computer displays changed and lights flickered on and off. Details below.

  • Solid Rocket Booster Separation
    • Cockpit Cues
    • Shortly before separation a flashing indication "PC < 50" appeared on the ASC TRAJ display, then disappeared at separation (red arrow 1). (This indicated that the chamber pressure in the boosters had dropped below 50 psi.)
    • After separation, the Major Mode number changed from 102 to 103 (red arrow 2)
    • After separation, the Main Engine Cutoff (MECO) time displayed (TMECO) started to converge (red arrow 3)

enter image description here

  • Visual / physiological cues
  • Large drop in X axis acceleration
  • Large decrease in magnitude of random vibration
  • Up-firing reaction control system jets and booster separation motor plumes visible out windows

  • External Tank Separation
    • Cockpit Cues
    • The three main engine status lights on the dashboard, which illuminated red at MECO, extinguished

enter image description here

  • the Major Mode number changed from 103 to 104 (red arrow 2 in first image)

  • Visual / physiological cues

  • Reaction control system jets fired to cause -Z translation

  • External Tank moves away as seen in forward windows

Additional information: Explanation of Major Modes vs. mission events

enter image description here

Sources:

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  • $\begingroup$ This is perfect! Thank you so much. Yes :) $\endgroup$
    – user36480
    Jan 6, 2021 at 18:55
  • $\begingroup$ Does the major mode refer to the program being executed by chance? Pitchover, gravity turn, powered explicit guidance, orbital insertion, say? Or is it something else altogether? Thanks again! $\endgroup$
    – user36480
    Jan 6, 2021 at 19:04
  • $\begingroup$ @Alex thanks for the comment. Will add explanatory diagram. $\endgroup$ Jan 6, 2021 at 19:28
  • $\begingroup$ @Organic_Marble: Thanks again! This clarifies everything. $\endgroup$
    – user36480
    Jan 7, 2021 at 0:06

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