SpaceX COTS Demo 1 Updates

[iamlucky13]

The most likely path forward is that we will trim off the thinnest portion of the nozzle extension, which is where the cracks are located, perform a thorough systems check and resume launch preparation.
Both from SpaceX.

Aha...the old 5-axis hand mill solution. (Also known as an intern with a Dremel)

(laughed so hard at that one...)

Me too.  I'd hate to be the person who had to trim say an inch off of a 9ft thin-wall nozzle...without causing more damage...

   ROFL. Roughing out niobium with a none-too-sharp blade was not my favorite time on the bandsaw. Hope they have plenty of dremel tips. And another intern with a good vacuum wand. (And, following Lee Jay's remark, a massage therapist!)
     -Alex

edit: typo name

Actually, if it's really only 0.3mm thick (about 0.012" or 30 gauge or half a dozen sheets of paper worth), I bet it would cut reasonably easily with aviation shears. Never having worked on a rocket nozzle, however, I can only guess whether that would produce an acceptable cut.

I've also never had to do a...what...maybe 20 foot long cut if they have to do the whole circumference? Talk about a hand cramp. Might it be acceptable just to scallop the affected area, and maybe the opposite side if they want to balance it?

On the other hand, it doesn't sound conclusive quite yet they won't decide the issue is serious enough to warrant replacing the whole nozzle extension.

[JohnWT]

Aviation shears?  Hand cramp?  Dremel?  Surely you jest.

They can rotate the vehicle on its horizontal stand.  I would expect that they would use a suitable non distorting cutter (laser?) to trim the end off as they rotate the vehicle.

[AS-503]

I think they are going to fly Chuck Norris in to cut it with a karate chop.

[iamlucky13]

Aviation shears?  Hand cramp?  Dremel?  Surely you jest.

They can rotate the vehicle on its horizontal stand.  I would expect that they would use a suitable non distorting cutter (laser?) to trim the end off as they rotate the vehicle.

Which goes back to the question of whether they can rollback, demate the stage, cut, remate, and rollout for a launch in the current NET (Wednesday or Thursday?).

So partially I was jesting, but partially I was thinking through ways to do this with minimal work. The question of whether or not those might yield acceptable cuts was serious.

SpaceX has previously stated (after the Falcon 1 nozzle impact during staging) that a niobium nozzle is pretty dent-tolerant. A wavy hand-cut seems like it should be acceptable, but on the other hand, if they crimp the metal a bit at every stroke as sometimes happens with shears, that could be more serious.

[ugordan]

I guess he missed this one or knows something we don't.

Given what I've gathered so far, let's just say I'd trust nblackwell over Jay on this. You might consider there may be are other posters here involved with SpaceX one way or another, i.e. it's not Jim vs. everyone else.

If there's overly tolerant behavior for SpaceX' processes here, that doesn't mean "conspiracy" theories need to be made on the other side on how they get it easier at every step, compared to ULA or whatnot.

[joshcryer]

Falcon 9 Flight 1 was also 34.5 degrees, which caused a lot of hub hub over AU with regards to a glowing UFO. I'm with nblackwell on this one.

edit: I just spent the last hour or two playing with Orbiter, if they take relatively the same trajectory as Falcon 9 Flight 1 then on the second or third orbits it is passing quite nicely over, you guessed it, the Gulf of Mexico.

If you want to try it yourself you can grab Orbiter and the Falcon 9 plugin. It includes the Flight 1 scenario (including the nasty second stage rotation), so without having to do much fiddling, you can see that this trajectory fits well SpaceX's flight plan. It also explains (to me) why they only have 2.5/3 orbits at most, because the Gulf is a dwindling target on that trajectory.

I'm not an orbital mechanics guy by any means, but the evidence points to a similar flight plan to Falcon 9 Flight 1.

[tigerade]

Well, thankfully I have Wednesday and Thursday off.  I hope it will launch during one of those two days.  I am still not missing this thing!

[cuddihy]

You should know...so that is good.  So processing in your view is the only area of concern?   Was that your point about dancing in your post?

I was referring to people on this forum dancing around the point.    There processes (more than just ground ops) is my area of concern

Processes aren't everything, as shuttle has shown, the processes can be nailed down and you can still lose 7 astronauts.

For some managers "processes" and "CPI" replace good judgement and are a cover for lack of good leadership.

Not every problem is a process problem. And many process problems are just the wrong people in the job...

"Their processes," by the way, not "there".

[robertross]

Aviation shears?  Hand cramp?  Dremel?  Surely you jest.

They can rotate the vehicle on its horizontal stand.  I would expect that they would use a suitable non distorting cutter (laser?) to trim the end off as they rotate the vehicle.

Which goes back to the question of whether they can rollback, demate the stage, cut, remate, and rollout for a launch in the current NET (Wednesday or Thursday?).

So partially I was jesting, but partially I was thinking through ways to do this with minimal work. The question of whether or not those might yield acceptable cuts was serious.

SpaceX has previously stated (after the Falcon 1 nozzle impact during staging) that a niobium nozzle is pretty dent-tolerant. A wavy hand-cut seems like it should be acceptable, but on the other hand, if they crimp the metal a bit at every stroke as sometimes happens with shears, that could be more serious.

Yes, dent tolerant (as to performance and all that), but also very fragile. There are SpaceX pictures showing the nozzle with a note on the sidewall saying something to this effect.

We're talking pretty exotic stuff here. Heck, if you read the document I had posted earlier about Niobium, they had to use EB (electron beam) to melt this stuff adequately. It's also very susceptible to high temp oxidation, requiring a very good coating as a preventative. By using a dremel, or any machining process, they circumvent that coating (assuming the nozzle has said coating). Not saying it can't be done, but very tricky.

[ugordan]

Yes, dent tolerant (as to performance and all that), but also very fragile. There are SpaceX pictures showing the nozzle with a note on the sidewall saying something to this effect.

I read that the note was probably to prevent greasy fingers touching it which could prevent the coating from being properly applied, not because of fear of damage.

[Jim]

1.  Processes aren't everything, as shuttle has shown, the processes can be nailed down and you can still lose 7 astronauts.

2.  For some managers "processes" and "CPI" replace good judgement and are a cover for lack of good leadership.

3.  Not every problem is a process problem. And many process problems are just the wrong people in the job...

1.  It was a process failures that lost 14 astronauts
2.   good judgment is part of a process
3.  It is a process to place the right people in the right job

"judgment" by the way, not "judgement ".

[moose103]

I was referring to people on this forum dancing around the point.    There processes (more than just ground ops) is my area of concern

A person with expertise got a lot more out of that news than I did.  I couldn't figure out how they were seeing a cracked nozzle inside an assembled rocket. 

So this is my guess: you think they have old pictures of the broken nozzle from days or weeks ago, and only now is somebody noticing.  Something went wrong to let them assemble it with the broken nozzle in the first place.  Thus the bad process, and a drop in confidence of competence, meaning they might make another error.  Is that right?

"judgment" by the way, not "judgement ".

What is a their or a there between friends.  I think both get the message across

[Mike_1179]

So SpaceX (again) shows that they have some work to do to move up the Systems Engineering learning curve.  No one is saying their technical skills aren’t there, but rocket science is more than rocket science.

[go4mars]

"judgment" by the way, not "judgement ".

http://dictionary.cambridge.org/dictionary/british/judgment_1#judgment_1__3 

Just the American way vs. the U.K./Commonwealth way to spell it.  Neither is wrong. 

[pippin]

Hey, Jim's a rocket scientist, not a linguist

[butters]

In the scheme of things, I'd rather have the process problem of discovering problems inconveniently late in the flow and consequently delaying the launch than the process problem of knowing it may be unsafe to proceed and doing so anyway. From the former the team can learn to do things better next time, but the arrogance of the latter can only be untaught by catastrophic failure.

I'm still unclear as to when the cracks occurred, when they should have discovered the cracks, and whether they were sitting on evidence of the cracks for some amount of time without realizing it or doing anything about. So I don't see how any outsider with any amount of industry experience can authoritatively declare that there are process problems, much less speak to the nature of those problems.

[Jim]

I was referring to people on this forum dancing around the point.    There processes (more than just ground ops) is my area of concern

A person with expertise got a lot more out of that news than I did.  I couldn't figure out how they were seeing a cracked nozzle inside an assembled rocket. 

So this is my guess: you think they have old pictures of the broken nozzle from days or weeks ago, and only now is somebody noticing.  Something went wrong to let them assemble it with the broken nozzle in the first place.  Thus the bad process, and a drop in confidence of competence, meaning they might make another error.  Is that right?

Yes,  many process errors

1.  bad hardware was created and passed inspection

2.  Bad hardware was put into a flight vehicle.

3.  The review of closeout photos was not completed before the move to the next major phase in the ground flow

[Jim]

So I don't see how any outsider with any amount of industry experience can authoritatively declare that there are process problems,

Because they are blatantly obvious to the most casual of observers, unless one is drunk on koolade.

[gospacex]

According to SpaceX site, this is the photo of the first flight expansion nozzle for the Merlin Vacuum second stage engine:


and this is expansion nozzle for Falcon 9 Flight 2:

[corrodedNut]

So what's the latest word? Is it two small cracks or one 3 inch crack?

PS. You guys with the dremel tool, don't forget about the stiffening ring, you can use it as a straight edge, and you'll need a hot glue gun to put it back on.