SpaceX COTS Demo 2 Updates

[Halidon]

I don't have powerpoint on this laptop, do they give any detail at all about the "weld defects" or just that they exist?

[ugordan]

No detail given. Oddly enough, even though the presentation is dated to May 10, it still says the first stage is in Texas.

[Comga]

I don't have powerpoint on this laptop, do they give any detail at all about the "weld defects" or just that they exist?

"Second Stage delayed due to weld defects"  is the sum of the information.

[Comga]

New photo of COTS-1 Dragon in the water, taken from a helicopter or airplane.  They must have more photos.

Is it safe to say that the other previously released splashdown photos were taken from an aircraft? Having spotted the Dragon under 'chutes, taking pictures fom a distance, then moving in for a closer shot? Surely nothing ITAR related would prevent their release? I still find it hard to believe there's isn't any video.

There is video, just of such poor quality that they don't want to release it.  My guess is that the photography is from the boat, but that they didn't anticipate being so close to target, and were unprepared to take advantage of the short range.  The video is probably from an iPhone or such.

[dragon44]

SpaceX may have just assumed they would be too far away to bother with video. This was the first reentry for Dragon, so I'm guessing the boats were kept further out than we might imagine. Don't want to lose a boat if Dragon had broken up or the parachutes didn't work. Just a guess.

[Comga]

SpaceX may have just assumed they would be too far away to bother with video. This was the first reentry for Dragon, so I'm guessing the boats were kept further out than we might imagine. Don't want to lose a boat if Dragon had broken up or the parachutes didn't work. Just a guess.

That 's my guess too.  Their offset to the landing target is less than a tenth the median distance for Soyuz, as discussed elsewhere on NSF.  It is unlikely they thought it would be just that good.

[Robotbeat]

SpaceX may have just assumed they would be too far away to bother with video. This was the first reentry for Dragon, so I'm guessing the boats were kept further out than we might imagine. Don't want to lose a boat if Dragon had broken up or the parachutes didn't work. Just a guess.

That 's my guess too.  Their offset to the landing target is less than a tenth the median distance for Soyuz, as discussed elsewhere on NSF.  It is unlikely they thought it would be just that good.

Why not? Have you done the analysis?

If it didn't work as good, it's as likely as anything that it would've been VERY far off, in which case the risk to the boat would've been exceedingly small.

[Lurker Steve]

SpaceX may have just assumed they would be too far away to bother with video. This was the first reentry for Dragon, so I'm guessing the boats were kept further out than we might imagine. Don't want to lose a boat if Dragon had broken up or the parachutes didn't work. Just a guess.

That 's my guess too.  Their offset to the landing target is less than a tenth the median distance for Soyuz, as discussed elsewhere on NSF.  It is unlikely they thought it would be just that good.

Why not? Have you done the analysis?

If it didn't work as good, it's as likely as anything that it would've been VERY far off, in which case the risk to the boat would've been exceedingly small.

Well, I imagine the risk to the ship is greater on re-entry than the risk to any ship that happens to wander into the range at KSC on launch day. If you know a projectile is headed your way, don't park in the middle of the bullseye.

[MP99]

I don't have powerpoint on this laptop, do they give any detail at all about the "weld defects" or just that they exist?

If you have access rights to the machine (IE it's not a locked down corporate machine), then this free download should allow you to view (but not create) powerpoint files:-

http://www.microsoft.com/downloads/en/details.aspx?FamilyID=cb9bf144-1076-4615-9951-294eeb832823&pf=true

Should handle files from Powerpoint 97, 2000, 2002, 2003, 2007 & 2010.

cheers, Martin

PS there are links at the bottom of the page to viewers for Word & Excel, also.

[Jim]

Everybody is ignoring the tank welds and focusing on a trivial item as landing distance.

[kevin-rf]

Well, I imagine the risk to the ship is greater on re-entry than the risk to any ship that happens to wander into the range at KSC on launch day. If you know a projectile is headed your way, don't park in the middle of the bullseye.

I remember reading somewhere in the histories of the V-2 that the observation tower on one of the German test ranges was smack in the center of the bulls eye, under the theory you never quite hit the center, it is actually the "safest" place to be (the bit of text had them bailing out of it, because they managed to nail it with a test V2)

Considering how hard it is to track something at high mag with a video camera from a rolling deck, I would be very surprised if a high res video exists, and it is more likely the dragon was tracked at a low mag and is quite small compared to the rest of the frame.

[Jim]

There are weld defects on the second stage:
http://www.faa.gov/about/office_org/headquarters_offices/ast/advisory_committee/meeting_news/media/2011/may/Alexander.pptx

The golden program has some tarnish

[kevin-rf]

The golden program has some tarnish

Doesn't tell us which weld(s) is defective, now does it? Are these the friction stir welds that form the barrel, or hand welds use to integrate some of the plumbing into the tanks, or some other weld(s)? What is the defect, and can they be repaired?

[jimvela]

There are weld defects on the second stage:
http://www.faa.gov/about/office_org/headquarters_offices/ast/advisory_committee/meeting_news/media/2011/may/Alexander.pptx

The golden program has some tarnish

Developing a new launcher and getting it right for a launch or two when the majority of eyes and energy of the enterprise is focused on one build at a time is only the first hard part.

The next hard part is repeating it, time after time after time after.... when the best eyes and minds of the enterprise are then focused on some other endeavor or are spread thin across new development and sustaining production.

Automated manufacturing systems are only as good as the production people who operate, upgrade, and maintain them- defects happen even with the best automated manufacturing systems.

Then there are other hard parts (like maintaining legacy designs and avoiding cost spirals as you mature and evolve your processes and designs).

[Halidon]

The golden program has some tarnish

Doesn't tell us which weld(s) is defective, now does it? Are these the friction stir welds that form the barrel, or hand welds use to integrate some of the plumbing into the tanks, or some other weld(s)? What is the defect, and can they be repaired?

If they couldn't be repaired, or required too much effort to repair to be worth it, I imagine they'd skip over to their next upper stage in the pipleline. That they haven't done that, or at least aren't saying they have, suggests it's something they feel is fixable in a timely fashion.

As for "tarnish," I'm pleased to see their inspection and quality control program is doing well. Much rather find problems now that at T+1:30

[Jim]

As for "tarnish," I'm pleased to see their inspection and quality control program is doing well. Much rather find problems now that at T+1:30

There was an escape, since the tank became a stage.

jimvela echos a point that I have been making.  It is easy to design and build a rocket.  The hard part is doing it over and over again successfully.  It is things like this that increase the costs of doing business in the launch arena.  Things just keep popping.  Here is another scenario of something that could go "wrong' and cause delays.  While waiting for the second stage, the first stage just sits there.  Time goes by and eventually the second stage is delivered.  It becomes time to mate the stages and guess what?  They don't fit, it seems that the 1st stage developed a little ovality.  So they develop a fix and press on.  But again, more costs were incurred.  The crack in the nozzle was another thing.  This is what happens time after time.  Making a launch vehicle reliable takes people, which aren't cheap.

[dunderwood]

There was an escape, since the tank became a stage.

Do you have a source for that, other than the powerpoint which claims the 1st stage is in Texas when we've seen pictures of it in Florida several weeks ago?

[Comga]

Everybody is ignoring the tank welds and focusing on a trivial item as landing distance.

Not quite everybody, Jim

There are weld defects on the second stage:
http://www.faa.gov/about/office_org/headquarters_offices/ast/advisory_committee/meeting_news/media/2011/may/Alexander.pptx

...
Quality, quality!  Is the 2nd stage weld a harbinger or just one of those things?
...

I was waiting for you to comment.

Edit: To be precise, the PowerPoint says "Second Stage delayed due to weld defects."  It does not state that the weld was in a tank that "escaped" to be incorporated into the stage.  It could be that the weld was in the stage or that it was in a tank whose repair or replacement delayed assembly of the stage.  You probably have additional information.

[Comga]

SpaceX may have just assumed they would be too far away to bother with video. This was the first reentry for Dragon, so I'm guessing the boats were kept further out than we might imagine. Don't want to lose a boat if Dragon had broken up or the parachutes didn't work. Just a guess.

That 's my guess too.  Their offset to the landing target is less than a tenth the median distance for Soyuz, as discussed elsewhere on NSF. It is unlikely they thought it would be just that good.

Why not? Have you done the analysis?

Why not? Because Gwynne Shotwell said it was a surprise, right in her first post-landing press conference. 

[edkyle99]

As for "tarnish," I'm pleased to see their inspection and quality control program is doing well. Much rather find problems now that at T+1:30

There was an escape, since the tank became a stage.

jimvela echos a point that I have been making.  It is easy to design and build a rocket.  The hard part is doing it over and over again successfully.  It is things like this that increase the costs of doing business in the launch arena.  Things just keep popping.  Here is another scenario of something that could go "wrong' and cause delays.  While waiting for the second stage, the first stage just sits there.  Time goes by and eventually the second stage is delivered.  It becomes time to mate the stages and guess what?  They don't fit, it seems that the 1st stage developed a little ovality.  So they develop a fix and press on.  But again, more costs were incurred.  The crack in the nozzle was another thing.  This is what happens time after time.  Making a launch vehicle reliable takes people, which aren't cheap.

Yep.  Consider that the first Saturn V S-IC propellant tanks were scrapped due to bad welds.  A bad weld repair caused an S-II bulkhead to fail during testing.  The first Saturn V had to be de-stacked when cracks were found in S-II stage welds.  An S-IVB flight stage exploded during an acceptance test when a pressurant tank weld failed.  Bad welds caused plenty of problems with early Atlas and Centaur stages.  Most of the early Titan missiles leaked.  And so on.

 - Ed Kyle