SpaceX Starship SN4 explodes during engine test

[capngrog]

The SpaceX Starship SN4 Raptor Engine exploded on the test stand after an engine static fire test run (29/05/2020) at the facility in Boca Chica, Texas. Below is a link to the story. If the link is not active, just copy and paste it in your browser.

https://techcrunch.com/2020/05/29/spacexs-starship-sn4-launch-vehicle-prototype-explodes-after-static-engine-fire-test/

If you look at approximately the 1:22:32 point on the 2 hour NASA video, you'll see the Raptor engine fire for just a second or two, then shut down. At approximately 1:24:48 of the video, the explosion occurs. It looks like the Starship SN4 Raptor Engine is no more. Apparently, nobody was injured in this incident.

Cheers,
Grog

[atakacs]

I muss confess that I am someone baffled by this whole Starship thing... Obviously mishaps can occur but you usually test discrete components and when you are reasonably convinced they will work reliably you assemble the whole thing for an actual test launch. What's the point of blowing 4 full rockets without even getting off the ground ? Seems a very weird way of operating.

[tdracer]

I muss confess that I am someone baffled by this whole Starship thing... Obviously mishaps can occur but you usually test discrete components and and you are reasonably convinced they will work reliably you assemble the whole thing for an actual test launch. What's the point of blowing 4 full rockets without even getting off the ground ? Seems a very weird way of operating.
You can't test everything in isolation and be done. At some point you need to test the launch configuration to find out what sort of interactions you might experience. Without knowing anything this particular incident, it's quite possible they did in fact discover an unknown (and undesirable) interaction when all four engines are combined.

[MechEngr]

The explosion happened after the engine test was complete during the unused-fuel offloading phase. It does not appear to be caused by a flaw with the rocket, but instead the pipes carrying the liquid methane; possibly a failed or misoperated ground operations valve.

[etudiant]

I muss confess that I am someone baffled by this whole Starship thing... Obviously mishaps can occur but you usually test discrete components and when you are reasonably convinced they will work reliably you assemble the whole thing for an actual test launch. What's the point of blowing 4 full rockets without even getting off the ground ? Seems a very weird way of operating.

You are entirely correct, Musk is not blowing up whole rockets. The several 'Starships' that have failed so impressively are all plumbing prototypes, built to verify the structural and pressure integrity of this stainless steel pressure hull.
This most recent failed article would have eventually been outfitted to serve as a hopper test vehicle, but was lost on the first engine test firing.
The surprise to me is that this basic plumbing is so tricky, this is the third time that there appears to have been a valve sequencing malfunction.

[Senior Pilot]

Discussion here (https://www.pprune.org/jet-blast/554107-spacex-falcon-9-live-landing-attempt.html) post 191 :ok: