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Merged SpaceX’s Starship Rocket Explodes After Launch/Starship hop

crescent said:
:thumbsup:

It blew up - but not until it was done. And it did the thing with the engines, and going sideways, and belly flopping, then back up right again.

That was crazy.
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My reaction was that 7 out of 8 criteria for success were met.

  1. Launch successfully - tick
  2. Climb to target altitude - tick
  3. Transition to bellyflop position - tick
  4. Controlled descent - tick
  5. Transition to upright position - tick
  6. Relight engines - tick
  7. On target to landing site - tick
  8. Land without exploding -
 
a_unique_person said:
What's it like for the people in the Starship when it does the aerobatics?
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It's not especially aerobatic. Particularly when you consider that on a genuine mission, the craft would approach the atmosphere pretty much already in the bellyflop position, and the only manoeuvring required is the transition to upright just before landing. It'll be rough, but not too bad.
 
arthwollipot said:
My reaction was that 7 out of 8 criteria for success were met.

  1. Launch successfully - tick
  2. Climb to target altitude - tick
  3. Transition to bellyflop position - tick
  4. Controlled descent - tick
  5. Transition to upright position - tick
  6. Relight engines - tick
  7. On target to landing site - tick
  8. Land without exploding -
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A couple of other things it did that were important...

1A. Synchronized engine shutdowns and gimbaling to maintain the vehicle attitude during ascent.
1B. Translation while maintaining attitude to prepare for the pitch-over maneuver at target altitude (the vehicle needed to get "downrange" in order to pitch over and glide/skydive back to the landing pad)
 
smartcooky said:
A couple of other things it did that were important...

1A. Synchronized engine shutdowns and gimbaling to maintain the vehicle attitude during ascent.
1B. Translation while maintaining attitude to prepare for the pitch-over maneuver at target altitude (the vehicle needed to get "downrange" in order to pitch over and glide/skydive back to the landing pad)
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Indeed. So let's say 9/10 criteria for success. :)
 
arthwollipot said:
My reaction was that 7 out of 8 criteria for success were met.

  1. Launch successfully - tick
  2. Climb to target altitude - tick
  3. Transition to bellyflop position - tick
  4. Controlled descent - tick
  5. Transition to upright position - tick
  6. Relight engines - tick
  7. On target to landing site - tick
  8. Land without exploding -
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Not sure I'd give the tick on "relight engines". Yes they relit, but then began consuming themselves.
 
Trebuchet said:
Not sure I'd give the tick on "relight engines". Yes they relit, but then began consuming themselves.
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They got the vehicle oriented and a good way to the pad before they started having issues. The low fuel header pressure issues only had a visible effect a good bit after ignition, and if they were present at ignition the Raptors only deserve extra credit for successfully igniting under suboptimal conditions.
 
Can anyone link to a video where there is NOT an edit in the split second before the explosion?

Ward
 
smartcooky said:
SN9 has tipped over in the high bay and is leaning against one corner. Happened about 9:02am Friday morning.

https://twitter.com/BocaChicaGal/status/1337424248260993024

Looks like a stand might have buckled.
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Well damn, but its stainless steel so replacing parts should be straightforward, unlike the Orion capsule where a PDU failure could take months to repair:

https://www.theverge.com/2020/11/30/21726753/nasa-orion-crew-capsule-power-unit-failure-artemis-i
 
Bad news is the tilt damaged a fin, good news a replacement fin arrived within a few hours.
 
Trebuchet said:
Not sure I'd give the tick on "relight engines". Yes they relit, but then began consuming themselves.
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That was because of fuel starvation due to low pressure in the header tank, not a problem with the engine.

Lack of fuel causes the engines to run "Oxidizer Rich". AIUI (no doubt Jay will correct me if I'm wrong) when that happens, the oxygen will be chemically reacting with the best available candidate. Since the Raptor combustion chamber and nozzle contains copper, it will combine with that. This will cause the chamber temperature to spike, and since pure oxygen is very corrosive at high temperatures, the copper gets rapidly oxidized away, causing the bright green flame we saw.

The resulting sudden drop in thrust meant that the rocket fell too quickly to get fully upright and land safely.
 
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smartcooky said:
That was because of fuel starvation due to low pressure in the header tank, not a problem with the engine.

Lack of fuel causes the engines to run "Oxidizer Rich". AIUI (no doubt Jay will correct me if I'm wrong) when that happens, the oxygen will be chemically reacting with the best available candidate. Since the Raptor combustion chamber and nozzle contains copper, it will combine with that. This will cause the chamber temperature to spike, and since pure oxygen is very corrosive at high temperatures, the copper gets rapidly oxidized away, causing the bright green flame we saw.

The resulting sudden drop in thrust meant that the rocket fell too quickly to get fully upright and land safely.
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The fuel's also the coolant that keeps them from melting under normal operating conditions.
 
I note that S/N Nine, or Snine as I think of it, has had engines installed without first doing the pressure test with artificial thrust simulator. Definitely moving right along.
 
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