totm nov 2023 SpaceX Discussion Thread

[RCgothic]

My puzzle is that an engine would need to run LOX rich for quite a while to fall catastrophically. Surely they could just... turn the engine off? Which begs the question why didn't they?

Also whilst it's probably worth trying, low lox levels in the tank for a static fire probably wouldn't be sufficient to replicate the long duration and high G environment that may be causing harmonic vibration issues in flight in the ground.

[GuessingEveryDay]

Crew-10 delayed

[darthgently]

3 hours ago, RCgothic said:

 

My puzzle is that an engine would need to run LOX rich for quite a while to fall catastrophically. Surely they could just... turn the engine off? Which begs the question why didn't they?

 

The remaining engines not shutting off really is a puzzler.  But that assumes the software has a totally clear idea of what was happening back in the engine bay.  If it assumed some vectoring engines were still operating the goal may have been to regain attitude, keep chugging, and get the debris field out into the mid Atlantic instead of in the islands.

 It broke one of my KSP rules:  never thrust in the wrong direction.  My kOS scripts typically taper the throttle as attitude error goes up as a safety net.  No throttle, or just enough for vectoring steerage, if error is greater than 20 degrees or so on ascent.  This code typically only kicks in when I’m doing something new but it allows me to keep playing and testing for awhile rather than crashing and starting over.  Anyway, the point is that I’m not sure why they didn’t shut the remaining engines off, or at least throttle them down when pointed in the wrong direction.  They may have made it well past the islands, even doing endos, if they only throttled up when pointed down range with a positive pitch and tapered throttle down when not.  And maybe the engines were on for an reason but the software was confused about the attitude and available control authority

[tater]

 

[Exoscientist]

 
 Repeated engineering failures stem from the top. What SpaceX needs to do first is hire a true  Chief Engineer. Then follow standard industry practice of doing full-up(all engines), full mission duration, full thrust static tests.

  Bob Clark

[AckSed]

What is a true Chief Engineer?

Do they have aerospace experience?

Are they a respected expert in their field?

Do they have at least ten years of working at a rocket company?

Are they experienced with a high-pressure environment as they work with a team to push boundaries?

And are they also sensible and know when not to push the boundaries?

[Hotel26]

"The definition of insanity is doing the same thing over and over again and expecting different results",  Albert Einstein

[Lisias]

4 hours ago, AckSed said:

What is a true Chief Engineer?

Do they have aerospace experience?

Are they a respected expert in their field?

Do they have at least ten years of working at a rocket company?

Are they experienced with a high-pressure environment as they work with a team to push boundaries?

And are they also sensible and know when not to push the boundaries?

Are you saying that SpaceX put thousands of StarLink satellites in orbit, is launching resupply missions to ISS and created the first fully reusable 1st stage rocket (Falcon 9) without one?

[Hotel26]

Definition: "a true Chief Engineer has a pocket protector and is never seen without his slide rule."

[darthgently]

2 hours ago, Lisias said:

Are you saying that SpaceX put thousands of StarLink satellites in orbit, is launching resupply missions to ISS and created the first fully reusable 1st stage rocket (Falcon 9) without one?

I read it as meaning they couldn’t have done it without one.

[AckSed]

Nuance: I was trying to reframe the question but tired 3AM thinking turned it into a CV of what an imagined Chief Engineer 'should' be.

[Deddly]

5 hours ago, Hotel26 said:

"The definition of insanity is doing the same thing over and over again and expecting different results",  Albert Einstein

I thought that was the definition of KSP.

[Exoscientist]

5 hours ago, Lisias said:

Are you saying that SpaceX put thousands of StarLink satellites in orbit, is launching resupply missions to ISS and created the first fully reusable 1st stage rocket (Falcon 9) without one?

 

 6 out of 8 explosions of your rocket in flight is indicative of bad engineering. Making the same mistake again after your vehicle explodes causing it to explode twice in a row is indicative of bad engineering. For any other space company such poor engineering would result in severe questioning of the Chief Engineer.

 Unfortunately for SpaceX, the Chief Engineer is the owner of the company. Questioning him results in YOU being the one getting fired.

  Bob Clark