Watching the NASA Spaceflight video Astra Test Flight (Launch Vehicle 0006) linked below it seems the launch was terminated, but at least on the video there was no audible Earth-shattering kaboom.

Question: Roughly how high does a rocket have to get before the self-destruct becomes inaudible? Before it becomes Invisible (during the day, or night)?

my attempt at transcription:

T+ 00:00:00  1:33:38
T+ 00:00:52  1:34:30 (rocket now inaudible over the noisy ground LOX tank venting)
T+ 00:01:36  1:35:14 rocket has cleared the island 
T+ 00:01:56  1:35:34 approaching nominal downrange trajectory, tracking (330 m/s 13 km), 
T+ 00:02:02  1:35:40 and at this point we should have also passed max-Q
T+ 00:02:31  1:36:09 engine shuts off, rocket immediately starts rapidly rotating/tumbling
T+ 00:02:34  1:36:12 vehicle has passed through max-Q
T+ 00:02:38  1:36:16 terminate sent(?)
T+ 00:02:44  1:36:22 terminate received

cued at final countdown:

  • 6
    $\begingroup$ Astra's flight termination system doesn't destroy the rocket, just cuts its engines so it falls back to Earth. They timed MECO so it would fall into the first exclusion zone, but the rocket would have just impacted the Gulf of Alaska. No kaboom. spaceflightnow.com/2021/08/29/… youtu.be/x2jU5W4ehPE $\endgroup$
    – paulmrest
    Aug 31 at 0:53
  • $\begingroup$ @paulmrest Oh! While that does not directly answer my question, I think it's important enough to post as a supplementary answer as it directly addresses Marvin's timeless "Where's the Earth-shattering kaboom?" $\endgroup$
    – uhoh
    Aug 31 at 0:56
  • 4
    $\begingroup$ I don't think I know enough to write a supplementary answer, but a cop-out answer could be "it depends on what happens after the flight is terminated". Contemporary rockets are frequently "unzipped" and then break up, so at best you're going to get a fireball (assuming no SRBs). Failures that bypass the termination system (GPS IIR-1, AMOS-6) can definitely kaboom. If fusion rockets are ever used for getting to orbit, a failure could hypothetically result in a nuclear fusion explosion that would be visible very far away indeed. $\endgroup$
    – paulmrest
    Aug 31 at 2:03

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