SpaceX Falcon I Launch III - Build-up Thread

[Comga]

IIRC, the Kestrel nozzle is a single piece of Molybdenum, so weld-defect would probably imply the Merlin...

The Kerstel nozzle is Niobium.  From the Falcon 1 link on the SpaceX website:

"Kestrel is ablatively cooled in the chamber and throat and radiatively cooled in the nozzle, which is fabricated from a high strength niobium alloy. As a metal, niobium is highly resistant to cracking compared to carbon-carbon."

That does not effect your argument, but it is not a sure thing. Does anyone here know if the Krestel nozzle is attached by welding or fastened (as Antares has pointed out)?  SpaceX doesn't say it is made from one piece, but there was no obvious weld when we saw it glow in the video from the second launch.

[jimvela]

Equally interesting, who was the sharp-eyed inspector that, in the field and with field equipment found a flaw ONE TENTH OF A MILLIMETER LONG that escaped acceptance inspection in the comfort of a well-equipped metrology lab back in California?  I want to hire that guy (or gal)!

Respectfully, Antonio, no you don't- if you like flying regularly. :-)p.

In all seriousness, It was probably an eagle eyed customer QA whom saw something in a post-ship review, and wouldn't accept any use-as-is disposition.  I know a few of those pesky customer QAs.

[iamlucky13]

It's quite possible that the Kestrel nozzle is welded. It could be forged, but that's more typical of very high volume operations. Theoretically, forming a sheet of niobium into the nozzle shape, welding and grinding the seam, and heat-treating it is easier than using a multi-stage forging operation. Properly welded, ground, and heat treated, you'd never know there was a seam from the launch video, even with a defect much larger than 0.1mm.

And of course, then there's still the attachment to the combustion chamber, as mentioned, but I suspect they are dissimilar materials, and therefore either brazed or sweated together.

[WHAP]

In all seriousness, It was probably an eagle eyed customer QA whom saw something in a post-ship review, and wouldn't accept any use-as-is disposition.  I know a few of those pesky customer QAs.

"Eagle-eyed" is a compliment.  I don't think you meant it that way.  I certainly wouldn't.

[Antares]

Um, there are not yet customer QA's on SpaceX launches.

[Gov't Seagull]

I don't get the deal with the crack. Finding a 0.1-mm-long crack is a total fluke, given standard inspection methods. If they are afraid their nozzle could be sensitive to a 0.1-mm crack, they really have a problem, because there are surely lots more 0.1-mm cracks that they can't see. It's hard to detect anything shorter than about 1.0 mm.

Maybe they meant a 0.1-mm wide crack, but that is not the usual way to give the size of a crack.

[toddbronco2]

I don't get the deal with the crack. Finding a 0.1-mm-long crack is a total fluke, given standard inspection methods. If they are afraid their nozzle could be sensitive to a 0.1-mm crack, they really have a problem, because there are surely lots more 0.1-mm cracks that they can't see. It's hard to detect anything shorter than about 1.0 mm.

Maybe they meant a 0.1-mm wide crack, but that is not the usual way to give the size of a crack.

Yeah, I agree.  There's no way they're talking about a .1mm long crack.   I can barely even fathom how small that is and I do NOT believe that if I could even see the crack that I would be able to call it that.  I feel like 0.1 mm being the width of the crack is much more likely.

Also, people were talking about the forging/welding of the kestrel engine; I know a friend of mine working for SpaceX said that they used friction stir welding, but I don't think he said this specifically about the nozzle.  He was probably talking about the fuel tanks, since I don't know if friction stir welding works on the alloy they use for the nozzle.  I just thought I'd throw that out there in case somebody hadn't considered that.

[jongoff]

Also, people were talking about the forging/welding of the kestrel engine; I know a friend of mine working for SpaceX said that they used friction stir welding, but I don't think he said this specifically about the nozzle.  He was probably talking about the fuel tanks, since I don't know if friction stir welding works on the alloy they use for the nozzle.  I just thought I'd throw that out there in case somebody hadn't considered that.

No the nozzle extension is seam welded, thin-gauge material.  I think its Niobium?  Amazingly thin stuff.

~Jon

[guidanceisgo]

Any news on the poor guy who blew SpaceX's range story?  I doubt he will get to see the launch

[braddock]

Any news on the poor guy who blew SpaceX's range story?  I doubt he will get to see the launch

You mean the quoted Army Missile Command spokesman John Cummings?  He probably placed a call after he got word that the US Army takes Julys off...

...after all, why would the guys at RTS need to see fireworks?

[iamlucky13]

...after all, why would the guys at RTS need to see fireworks?

I don't know, I've got one cousin who works on ICBM's, and one cousin who works on ABM's, and both are generally pretty excited about blowing stuff up. Even they don't get enough of it at work.

[edkyle99]

I don't get the deal with the crack. Finding a 0.1-mm-long crack is a total fluke, given standard inspection methods. If they are afraid their nozzle could be sensitive to a 0.1-mm crack, they really have a problem, because there are surely lots more 0.1-mm cracks that they can't see. It's hard to detect anything shorter than about 1.0 mm.

Maybe they meant a 0.1-mm wide crack, but that is not the usual way to give the size of a crack.

Yeah, I agree.  There's no way they're talking about a .1mm long crack.   I can barely even fathom how small that is and I do NOT believe that if I could even see the crack that I would be able to call it that.  I feel like 0.1 mm being the width of the crack is much more likely.

The weld defect was not characterized as a crack by any information I have seen. Weld defects take other, more common forms, such as voids. The cited dimension is more in keeping with the size of a void.

Doesn't this imply that the defect was found in an X-ray?  Would an X-ray of this type have been performed at Omelek? 

 - Ed Kyle 

[iamlucky13]

You can have pits in the weld surface, too.

Alternately, something may have been found in other engines back at in El Segundo and prompted an inspection of this engine...x-ray, eye loop, surface roughness, etc.

[Avron]

Its very quiet.. have we no-one from Spacex here who can give us a hint?


Have they destacked? whats the forward plan?

[Chris-A]

Too quiet, Elon spoke at the royal aeronautical society, nothing informative about Flight 3.
http://www.flightglobal.com/blogs/hyperbola/2008/07/audio-spacex-ceo-elon-musk-spe.html
http://www.flightglobal.com/blogs/hyperbola/2008/07/musk-80-million-to-go-to-the-m.html

I'm guessing they're very tight lipped right now.

[koennecke]

I don't get the deal with the crack. Finding a 0.1-mm-long crack is a total fluke, given standard inspection methods. If they are afraid their nozzle could be sensitive to a 0.1-mm crack, they really have a problem, because there are surely lots more 0.1-mm cracks that they can't see. It's hard to detect anything shorter than about 1.0 mm.

Maybe they meant a 0.1-mm wide crack, but that is not the usual way to give the size of a crack.

Yeah, I agree.  There's no way they're talking about a .1mm long crack.   I can barely even fathom how small that is and I do NOT believe that if I could even see the crack that I would be able to call it that.  I feel like 0.1 mm being the width of the crack is much more likely.

The weld defect was not characterized as a crack by any information I have seen. Weld defects take other, more common forms, such as voids. The cited dimension is more in keeping with the size of a void.

A weld defect may also be a weld contamination.

[jabe]

Too quiet, Elon spoke at the royal aeronautical society, nothing informative about Flight 3.

I read "somewhere" (I thought it was a post in this thread but can't find it) that there was to be an article in a texas paper/media this past weekend about Spacex and its future plans.  Am I "losing it" or was it posted? 
jb
BTW I hate getting old

[aero313]

Too quiet, Elon spoke at the royal aeronautical society, nothing informative about Flight 3.
http://www.flightglobal.com/blogs/hyperbola/2008/07/audio-spacex-ceo-elon-musk-spe.html
http://www.flightglobal.com/blogs/hyperbola/2008/07/musk-80-million-to-go-to-the-m.html

I'm guessing they're very tight lipped right now.

Someone should mention to Elon that the Soyuz booster has only 5 engines, not nearly 27...

[Chris-A]

Too quiet, Elon spoke at the royal aeronautical society, nothing informative about Flight 3.

I read "somewhere" (I thought it was a post in this thread but can't find it) that there was to be an article in a texas paper/media this past weekend about Spacex and its future plans.  Am I "losing it" or was it posted? 
jb
BTW I hate getting old

Yes that would be from KCEN, http://www.kcentv.com/news/local-article-arch.php?nid=15699 (This link was the 5 engine test)

Also, Elon knows Soyuz has 5 engines. One of the AIAA conferences, he was comparing the Saturn-1b and Soyuz booster, the joke was Falcon 1's upper stage engine didn't exist without a turbopump

[Comga]

I read "somewhere" (I thought it was a post in this thread but can't find it) that there was to be an article in a texas paper/media this past weekend about Spacex and its future plans.  Am I "losing it" or was it posted? 
jb
BTW I hate getting old

In the article to which jabe provided a link, there was mention of another, larger article to come.
"Coming up in July NBC 6 News will have a special report on the local research being done by Space-X for future space travel. "
"July" doesn't limit them much.
You are not "losing it", at least not yet.  You still have time. :-P Don't get me started on "old".